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2.4 GHz Microstrip Patch Antenna Fabricated by Means of Laser Induced Graphitization of a Cellulose-based Flexible Substrate
Mukhtar Ahmad, Giuseppe Cantarella, Aurora Costa Angeli, Mallikarjun Madagalam, Christian Ebner, Enrico Avancini, Manuela Ciocca, Raheel Riaz, Pietro Ibba, Mattia Petrelli, Ignacio Merino, Nitzan Cohen, Paolo Lugli, Luisa Luisa
Faculty of Science and Technology,Free University of Bozen-Bolzano, Bolzano, Italy

Recently, laser-induced graphene (LIG) has received increasing attention as a valuable alternative to traditional printing techniques because of simplicity, low cost, and possibility to avoid using additional materials such as functional ink or adhesive layers. While there are several works on LIG supercapacitors, gas sensors, and triboelectric generators, this method is still very unexplored for antennas, especially those realized on eco-friendly paper substrates. In this work, we realized a 2.4 GHz microstrip patch antenna using laser induced graphitization on an environmentally friendly food-derived cellulose-based paper. The patch antenna was first designed and then simulated using High-Frequency Structure Simulator (HFSS) software and different values of the substrate relative permittivity (from 2 to 3.6), to understand the shift in the resonance frequency of the antenna after substrate graphitization. The resulting fabricated antenna showed strong resonance peak of -25dB at 2.4 GHz (corresponding to a substrate relative permittivity of 2.2 in sufficient agreement with experimental data). This makes the antenna suitable for ISM band, such as Wi-Fi, Bluetooth, and Zigbee.
Session: Abstract Session 3
An additively manufactured pressure measurement system based on optical sensors
Farzad Ahmadi1, Jeremy Siegfried2, Eric MacDonald1, Farzad Ahmadi1
1Rayen School of Engineering, Youngstown State University, Youngstown, OH, USA, 2Mechanical Engineering, College of Engineering, University of Texas at El Paso, El Paso, TX, USA

In this paper, a pressure measurement system is proposed based on reflective optical sensors. An array of nine sensors was embedded into a 3D multi-stack printed sample made of silicone rubber. The sample consisted of nine rectangular cells. The fabricated sample was designed to operate in medium- to high-pressure regimes. A customized Java-based application was developed to synchronize and automate the measurement process between a motorized force measurement test stand and a data acquisition system. The compression tests of a single cell showed good linearity and a dynamic range. Sensitivity and dynamic ranges of 0.001 kPa−1 and 1040 kPa, respectively, were obtained. Depending on the application, the sensitivity and dynamic range can be adjusted by changing the wall thickness of the cells. The proposed system exhibited good repeatability, durability, and dynamic stability over a wide range of applied pressures. The proposed pressure system has potential applications in sports biomechanics and health-monitoring systems.
Session: Abstract Session 2
Investigating the Impact of Thickness, Calendering and Channel Structures of Printed Electrodes on the Energy Density of LIBs - 3D Simulation and Validation
Soma Ahmadi1, Guanyi Wang2, Dinesh Maddipatla1, Qingliu Wu2, Wenquan Lu3, Massood Zandi Atashbar1
1Western Michigan University, Kalamazoo, MI, USA, 2Western Michigan University, Kalamazoo, MI, USA, 33Argon National Laboratory, Lemont, IL, USA

Abstract—Current lithium ion batteries (LIBs) are expensive and bulky, limited by relatively low charging rates. To increase the rate of charging and reduce weight, thin electrodes with high energy density are required. The increase in energy density can be achieved by several techniques including boosting electrolyte transport, high loading/utilization of active material, employing high conductive electrolytes and electrodes with advanced architectures, and increasing cell temperature. In this paper, a 3D physics-based electrochemical model of LIBs is developed in COMSOL simulation software for different thickness, calendering steps as well as channel structures (conical, cylindrical) to optimize the electrode design and in turn maximize volumetric energy density. The simulation results demonstrated that calendering the electrodes with high initial porosity increases the volumetric energy density of the cell. In addition, cylindrical channel structures with relatively lower edge-to-edge distance also results in increased volumetric energy density. The simulation results of the 3D model was validated by comparing it with experimental results.
Session: Abstract Session 5
Manufacturing of Low Cost Wearable Human Health Monitoring Devices
Azar Alizadeh
GE Research,

Wireless wearable devices can continuously assess and communicate the condition of patients and are crucial components of digital mobile health platforms. General societal trends across the globe, including a shortage of centralized laboratory and medical facilities, aging populations with increasing incidence of infectious and chronic diseases, earlier diagnosis of diseases, personalized medicine, companion testing for pharmaceutical use, government initiatives and insurance acceptance, are all important factors behind the demand for reliable, low-cost, wireless, wearable health monitoring and medical devices. Fortunately, technological building blocks for implementation of these devices have evolved to the point that we believe that such monitoring will progress into a fully mobile approach in a near future, enabling continuous monitoring across acute, ambulatory and home care. In the past decade, a number of wireless physiological monitoring devices have been developed and tested in various clinical settings and a few of them are at early stages of product release. Furthermore, in 2020, due to the unprecedented circumstances of the COVID-19 pandemic, numerous wearable devices were investigated for early infection detection and patient monitoring in hospital and nursing home settings. In spite of this tremendous potential and significant investments by both device developers and government agencies, broad adoption of wearable medical devices has not fully realized yet. The barriers to broad adoption include device cost and performance challenges, ease of use, integration of devices within the remote care flow system as well as lack of robust reimbursement models. In this talk, we will discuss flexible hybrid electronic manufacturing opportunities and challenges to create low cost, high performance wireless sensor systems for patient monitoring. We will highlight the critical need and progress towards: 1- enabling the supply chain workflows that allow for low cost and sustainable manufacturing solutions at large volumes, 2- partnerships with the medical community and end-user communities (patients and warfighters) to conduct well-designed human subjects studies and clinical trials that allow for an independent assessment and refinement of these devices with a direct feedback from end-users. A Principal Scientist at GE Research, Dr. Azar Alizadeh is the Principal Investigator on multiple US Department of Defense (DARPA, NextFlex and NBMC- AFRL) sponsored programs and leads cross-functional teams of industrial and academic partners to develop advanced computational platforms and wireless health and performance monitoring systems. The wearable sensing platforms developed by these teams enable vital signs as well as sweat and interstitial biochemical measurement capabilities and have the potential to revolutionize medicine and performance monitoring through early detection of illness, infection, fatigue and injury. Dr. Alizadeh holds a PhD in physics, is a NextFlex fellow, has co-authored 50 peer reviewed publications, and holds 20 US patents/patent applications. Dr. Alizadeh is the co-Lead on the NextFlex Human Monitoring Systems and serves on the Governing Council of NBMC. Dr Alizadeh is the recipient of GE 2019 Edison Award and Semi Flexi 2017 Award.
Session: Plenary Session 4
Reinventing Electronics for a Flexible World
Feras Alkhalil

Dr. Feras Alkhalil joined PragmatIC in September 2015 and leads the research and development activities at PragmatIC. He received his MSc and Ph.D. from the University of Southampton in Microelectronics System Design and Solid-State Electronics, respectively. Feras is a visiting fellow at Durham University, Department of Physics since September 2017, he holds 5 patents and has published in over 15 international journals.
Session: Invited Session 1 - Devices
Printable Nanoelectronics via Innovative Manufacturing Paradigms
Thomas Anthopoulos
King Abdullah University of Science and Technology (KAUST),

The relentless downscaling of the silicon transistor has been the primary driving force behind the continuous innovations witnessed in the traditional semiconductor industry over the past fifty years. However, adopting a similar approach to emerging semiconductor technologies has proven challenging both in terms of technology and economics. In this talk I will discuss the various challenges that such emerging technologies face in combing upscalable manufacturing methods with the required performance specifications, followed by the presentation of recent important accomplishments. Particular emphasis will be placed on work from our laboratory on new materials and processing paradigms for the development of nanostructured large-volume (opto)electronics for use in sensing, energy harvesting and radio frequency telecommunication systems of the future. Thomas D. Anthopoulos is a Professor of Material Science and Engineering at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. He received his B.Eng. and D.Phil. degrees from Staffordshire University in UK. He then spent two years at the University of St. Andrews (UK) where he worked on organic semiconductors for application in light-emitting diodes before join Philips Research Laboratories in The Netherlands to focus on printable microelectronics. From 2006 to 2017 he held faculty positions at Imperial College London (UK), first as an EPSRC Advanced Fellow and later as a Reader and full Professor of Experimental Physics. His research interests are diverse and cover the development and application of novel processing paradigms and the physics, chemistry & application of functional materials.
Session: Plenary Session 3
Organic Transistor Materials for Organic Liquid Crystal Displays
Mike Banach

Active matrix backplanes on glass almost exclusively use hard ceramic based materials as the basis for the fundamental transistor technology. To enable flexible displays and electronics, FlexEnable has pioneered an alternative manufacturing approach with soft, flexible organic materials as the active layers. In this talk we will review the best in class organic transistor materials and their fundamental electrical performance. We will also discuss how these materials enable plastic liquid displays with unique form factors. Mike Banach is the Technical Director at FlexEnable. He started his career as a researcher in flexible electronics at the Air Force Research Laboratories at Wright Patterson Air Force Base in USA. He joined FlexEnable in 2003 and has played an instrumental role in developing and industrialising its proprietary flexible electronic technology. As technical director, Mike has lead the team behind breakthrough technology developments with organic transistors including OLED and LCD displays and digital circuit applications. He holds a doctorate degree from the University of Cambridge and a BA from the University of Cincinnati.
Session: Invited Session 2 - Devices
Skin-Inspired Organic Electronics
Zhenan Bao
Stanford University,

Skin is the body’s largest organ, and is responsible for the transduction of a vast amount of information. This conformable, stretchable, self-healable and biodegradable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of electronic materials, inspired by the complexity of this organ is a tremendous, unrealized materials challenge. However, the advent of organic-based electronic materials may offer a potential solution to this longstanding problem. Over the past decade, we have developed materials design concepts to add skin-like functions to organic electronic materials without compromising their electronic properties. These new materials and new devices enabled arrange of new applications in medical devices, robotics and wearable electronics. In this talk, I will discuss several projects related to engineering conductive materials and developing fabrication methods to allow electronics with effective electrical interfaces with biological systems, through tuning their electrical as well as mechanical properties. The end result is a soft electrical interface that has both low interfacial impedance as well as match mechanical properties with biological tissue. Several new concepts, such as “morphing electronics” and “genetically targeted chemical assembly - GTCA” will be presented. Zhenan Bao is Department Chair and K.K. Lee Professor of Chemical Engineering, and by courtesy, a Professor of Chemistry and a Professor of Material Science and Engineering at Stanford University. Bao founded the Stanford Wearable Electronics Initiate (eWEAR) in 2016 and serves as the faculty director. Prior to joining Stanford in 2004, she was a Distinguished Member of Technical Staff in Bell Labs, Lucent Technologies from 1995-2004. She received her Ph.D in Chemistry from the University of Chicago in 1995. She has over 550 refereed publications and over 65 US patents with a Google Scholar H-Index >160. Bao is a co-founder and on the Board of Directors for C3 Nano and PyrAmes, both are silicon-valley venture funded start-ups. She serves as an advising Partner for Fusion Venture Capital.
Session: Plenary Session 5 / Closing
Engineering current-voltage linearity in TFTsfor analog and neuromorphic computing
Eva Bestelink1, Olivier de Sagazan2, Radu A Sporea1
1University of Surrey, Guildford, United Kingdom, 2IETR-DMM-UMR6164, University of Rennes, Rennes, France

Many emerging large area electronic applications (LAE) would benefit from a fully linear dependence of a transistor's output on its input, when operating in saturation, for reduced distortion and facile design of linear functions. While linearity is usually not inherent in FET-type TFTs, it has been observed over a limited range in contact-controlled devices, e.g. source-gated transistors (SGTs). Advantageous directly proportional dependence can be achieved, by design, in newly-developed multimodal thin-film transistors (MMTs), which share SGT charge injection principles and benefits: high gain; reduced saturation voltage; energy-efficiency; and manufacturing robustness. Unlike other TFTs, the switching function of an MMT is separately controlled from its charge injection in the source region with use of multiple gates. The built-in sample-and-hold feature of the channel control gate gives rise to new device and circuit functionality, lending itself towards extremely compact circuits, e.g. multiplying digital-to-analog-converters. Circuits such as these heavily rely on the MMT's linear transfer curve for its performance. Using Silvaco TCAD simulations, we reveal the effects of several design parameters on linear behaviour: source-gate overlap (S); semiconductor and insulator thicknesses (ts, ti); and mobility. The properties of the materials and layer geometries effectively influence the resistance in the source region, both horizontally and vertically, thus determining the nature of the potential in the semiconductor along S. In order to achieve a directly proportional dependence of drain current on input gate voltage, the whole of the source needs to contribute to charge injection from low source control gate voltages. Hence, for a material system, several design parameters can be tuned to tailor the linear performance of the transfer characteristic. The versatile operation of the MMT and its ability to produce a directly proportional output-input dependence allows for compact design of LAE applications e.g. sensing arrays, low distortion amplifiers or multilevel logic.
Session: Abstract Session 2
Flexible Thin Film Transistor (TFT) and Circuits for Internet of Things (IoT) based on Solution processed Indium Gallium Zinc Oxide (IGZO)
Sagar R Bhalerao1, Donald Lupo1, Paul R Berger1,2
1Tampere University, Tampere, Finland, 2The Ohio State University, Columbus, OH, USA

Solution-processed metal oxide semiconductors are being extensively studied as a channel material for active semiconductor transistors. Among all metal oxide semiconductors, indium-gallium-zinc-oxide (IGZO) gained considerable attention for thin film transistors (TFTs) due to its promising electrical properties. Although metal oxide TFTs fabricated with vacuum deposition techniques enjoy the advantage of higher mobility in comparison with solution processing, vacuum deposition techniques are very costly due to expensive equipment, restricting its usage for emerging modern technologies, such as printed and flexible electronics. On the other hand, solution-processed metal oxide devices have an added advantage such as low cost, and compatible for flexible substrates. Therefore, developments of solution processed metal oxide TFTs on flexible substrates could open a new era of flexible and wearable electronics. Herein, we report the fabrication of flexible thin film transistors (TFT) and inverter circuit using solution-processed indium-gallium-zinc-oxide (IGZO) as a channel material by uniting with room temperature deposited anodized high-κ aluminium oxide (Al2O3) for gate dielectrics. The flexible TFTs operates at low voltage Vds of 4 V, with threshold voltage Vth 1.05 V along with hysteresis as low as 0.4 V. The extracted electron mobility (µ) at saturation regime, is 4.77 cm2/V⋅s. The transconductance, gm, is 90.8 µS, subthreshold swing (SS) 357 mV/dec and on/off ratio 105.
Session: Abstract Session 1
Flexible Gallium Oxide (Ga2O3) Thin Film Transistors (TFTs) and Circuits for the Internet of Things (IoT)
Sagar R Bhalerao1, Donald Lupo1, Paul R Berger1, 2
1Department of Electrical Engineering, Tampere University, Tampere, Finland, 2Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, USA

Even though present advanced silicon-based devices and technology could be reaching their zenith of performance levels, still there are many orthogonal applications, which are yet far from their reach. However, due their high process temperatures, there are still a number of applications that are out-of-reach for silicon, namely direct integration into flexible and printed electronics, as opposed to a hybrid integration of adding a prefabricated integrated circuit. These can find usage in low-cost and disposable wearable medical technologies. Therefore, low temperature-solution processed oxide semiconductors that are complimentary to the performance of silicon are prerequisite for the forthcoming printed, flexible and wearable electronics revolution. Here, solution processed, flexible gallium oxide (Ga2O3) thin film transistors (TFT) and inverter circuit are reported. The high-κ aluminum oxide (Al2O3) for the gate dielectric, was deposited with the help of a room temperature anodization process. The gallium oxide TFTs show high performance, with extracted electron mobility (µ) 2.74 cm2/V⋅s, operating voltage as low as 3V and threshold voltage (Vth) 0.61 V. The on/off ratio 104 and subthreshold swing (SS) 0.5 V/dec, Hysteresis 0.1 V and transconductance, gm, is 64.8 µS.
Session: Abstract Session 4
Study of low temperature processing of HfO2 thin films by rf magnetron sputtering for flexible thin film transistors
Deepa Bhatt2, Shivam Nigam3, Siddhartha Panda1,2,3
12, Kanpur, India, 23, Kanpur, India, 31, Kanpur, India

Flexible thin film transistors have attracted huge interest for sensing application because of its real time monitoring of human health. The light weight and low temperature processing of such devices makes them promising for point of care diagnosis. For the low temperature processing of flexible thin film transistors choice of gate oxide, semiconductors and the interface between them are the important parameters. Hafnium oxide films have elucidated interest in the field-effect transistors because of the high dielectric constant, high band gap and the good interface with amorphous indium gallium zinc oxide semiconductors. In this work the sputtered deposition and post-annealing of hafnium oxide was studied for reduction of defects at the surface of gate dielectric. The hafnium oxide deposited by rf magnetron sputtering in argon atmosphere and in the argon and oxygen atmosphere for studying the film quality for sensing applications. AFM, XPS, XRD and FTIR material characterization were done for the demonstration of the properties of HfO2. Metal-Insulator-Metal characterization were done for the demonstration of the capacitance of the thin film for chemical and bio-sensing applications. The surface roughness of 4 nm making these material promising for sensing applications at room temperature. Key words: Flexible substrates, Hafnium oxide, thin film transistors, low temperature processing
Session: Abstract Session 1
Towards Efficient and Stable Printed Single-Layer OLEDs
Paul W.M. Blom
Max Planck Institute for Polymer Research,

The efficiency and stability of single-layer polymer light-emitting diodes is compromised by unbalanced charge transport, absence of triplet-exciton harvesting and low photoluminescence quantum efficiencies. We demonstrate that tuning the energy levels of the organic semiconductor can prevent charge trapping, which is the main cause of unbalanced charge transport, resulting in a symmetric broadened emission zone. A broadened recombination zone is beneficial for the lifetime of organic light-emitting diodes (OLEDs), but its effect on the optical outcoupling efficiency is unknown. By combining an electrical and optical model we demonstrate that the total outcoupling can be calculated as the integral of the outcoupling efficiency over different positions of emitting dipoles, weighted by the sum-normalized recombination profile, as obtained from electrical modeling. For a single-layer OLED based on the thermally delayed activated fluorescence emitter 9,10-bis(4-(9H-carbazol-9-yl)-2,6-dimethylphenyl)-9,10-diboraanthracene (CzDBA) the outcoupling efficiency to air mode can be as high as ~24%. As a result, single-layer devices with a broadened emission zone can achieve similar outcoupling efficiency to multilayer OLEDs establishing a route to efficient, stable, and simplified OLEDs. Paul W.M. Blom received his Ph. D. Degree in 1992 from the Technical University Eindhoven on picosecond charge carrier dynamics in GaAs. At Philips Research Laboratories he was engaged in the electro-optical properties of polymer light-emitting diodes. From 2000 he held a professorship at the University of Groningen in the field of electrical and optical properties of organic semiconducting devices. In September 2008 he became Scientific Director of the Holst Centre in Eindhoven, where the focus is on foil-based electronics, followed in 2012 by an appointment as
Session: Invited Session 3 - Chemistry & Materials
Inactivation of B. subtilis Spores Using Flexible Microplasma Discharge Device
Arnesh K Bose, Carol L Beaver, Dinesh Maddipatla, Silvia Rossbach, Massood Atashbar
Western Michigan University, Kalamazoo, MI, USA

A flexible microplasma discharge device (MDD) was successfully fabricated for inactivating spore forming bacteria such as Bacillus subtilis. The device was operated under ambient conditions using ambient air as the inactivating agent. A flexible polyethylene terephthalate (PET) film was employed as the dielectric layer and sandwiched between layers of flexible copper tape. The top and bottom electrodes were laser ablated in a honeycomb and circular pattern, respectively. The efficacy of the MDD was analyzed by irradiating microplasma on to the surface of agar on a petri dish, that was inoculated with B. subtilis. One- and seven-days old culture of B. subtilis were used to investigate the effectiveness of MDD for varying treatment time. It was observed that the device was able to inactivate both one- and seven-days old culture of B subtilis from only one second of exposure time and achieved 4log10 reduction. The performance of the MDD towards vegetative and sporulated cells of B. subtilis are analyzed and presented in this paper.
Session: Abstract Session 6
Solution Processed Organic Photodetectors: Science, Technology and Applications
A.J.J.M. (Albert) Breemen
Holst Centre/TNO, Eindhoven, The Netherlands,

Thanks to their low-temperature processing on large-area flexible substrates thin-film organic photodetectors (OPDs) are very attractive for a range of large area imaging and sensing applications. The presentation will consist of two parts. In the first part I will focus on better understanding the physical mechanisms that determine the intrinsic limits of the detectivity of OPDs, in particular the dark current in relation to dark injection and charge generation-recombination currents. In the second part will present some recent developments in realizing curved X-ray detectors and -upon integration with OLED displays - biometric scanners that can accurately image finger-, palm and vein patterns and simultaneously record PPG signals that can be used to monitor health parameters such as heart beat, oxygen saturation and blood pressure, thus demonstrating the advantages of organic photodiodes in high-resolution, flexible large-area photodetectors. Prof. Dr. G.H. Gelinck holds a Ph.D degree in physics of electrical functional polymers from the Technical University of Delft. In 1998 Gerwin joined the Philips Research Polymer Electronics cluster as a Senior Scientist, where he researched material and device aspects of organic thin-film transistors, with an emphasis on potential applications such as RF tags and AM displays. He headed the technology team that reported through scientific papers groundbreaking work on the use of polymer transistors in integrated circuits and tags, flexible displays and reprogrammable memories.. He was co-founder and Chief Scientist of Polymer Vision from 2002-2006. In 2007 Gerwin joint TNO/Holst Centre as Program manager/director, leading an international team of ~20 researchers. He is appointed as full professor at the University of Eindhoven in the Applied Physics Department per Sept 1st 2014. Since 2019 he is CTO of TNO/Holst Centre. Gerwin is the (co-)author of over 125 scientific papers on electrical functional polymers and polymeric devices and holds more than 25 patent applications and filings. His research interests include novel solution-processed semiconductors, fundamental charge and energy transport in these disordered materials in thin-film transistors, photodiodes and polymer actuators, and applications based on these materials/devices. .
Session: Invited Session 5 - Devices & Systems
From Flexible Perovskite Solar Cells to Large Area Modules: Challenges and Perspectives
Francesca Brunetti
University of Rome Tor Vergata Via del Politecnico,

Flexible perovskite solar cells (FPSCs) are prime candidates for several applications like consumer electronics, avionic and spacecraft where bendability, conformability and high power-to-weight ratio are required. Despite record efficiencies of lab-scale flexible devices (19.5% on 0.1 cm2 area), FPSCs are still lagging behind their rigid counterparts, which in very short time have rocketed 25.2% efficiency. Several questions related to these devices are still open and represent critical factors towards the commercialization of this technology: which are the demanding aspects to face when moving from rigid to flexible substrates? What are the strategies necessary to scale up from flexible perovskite solar cells to modules (FPSMs) using large-area automated techniques? How can the stability issue be addressed for flexible devices? This talk will explore possible answers to those questions showing also an example of a potential application of FPSMs in the field of flexible portable electronics. Prof. Francesca Brunetti received her PhD in Telecommunications and Microelectronics from the University of Rome Tor Vergata in 2005. In 2005, she was awarded of a Marie Curie Individual Fellowship spent in the Institute for Nanoelectronics of the Technical University of Munich, Germany. In 2006 she became researcher in the Department of Electronic Engineering of the University of Rome Tor Vergata, and since 2018, she is associated professor at the same Department. Cofounder of the Centre for Hybrid and Organic Solar Energy at the University of Rome Tor Vergata (CHOSE, her current research is focused on the analysis, design and manufacture of electronic and optoelectronic devices. In particular, her attention is focused on organic photodetectors for applications in low cost optical communications, third-generation organic solar cells on flexible substrates, graphene for application in organic solar cells, perovskite solar cells and large are modules. Recently, she started an activity on the realization of supercapacitors on flexible and recyclable substrates, among which paper. Prof. Brunetti has published more than 60 articles in the most prestigious international journals, she holds 5 patents. She is associated editor of the journal "Sustainable Energy and Fuels" (RSC).
Session: Invited Session 1 - Devices
Hybrid Systems-in-Foil – Enabler of High-performance Flexible Electronics
Joachim Burghartz, Zili Yu
Institut für Mikroelektronik Stuttgart (IMS CHIPS), Stuttgart, Germany

Flexible electronics add mechanical flexibility, adaptivity and stretchability as well as large-area placeability to electronic systems, thus allowing for conquering fundamentally new markets in consumer and commercial applications. Hybrid assembly of large-area devices and ultra-thin silicon chips on flexible substrates is now viewed as an enabler to high-performance and reliable industrial solutions as well as high-end consumer applications of flexible electronics. This talk discusses issues in ultra-thin chip fabrication, device modeling and circuit design under bending stress, on- versus off-chip sensor implementation, as well as assembly and interconnects for thin chips and distributed large-area components in Hybrid Systems-in-Foil (HySiF). Several distinct application examples are given to illustrate the advantages of the HySiF approach.
Session: Invited Session 5 - Devices & Systems
Pushing the Limits of Printed and Flexible Organic Electronics: Thin, Fast and … Edible
Mario Caironi
Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia,

Printed polymer field-effect transistors (FETs) have been considered for many novel applications towards large area and flexible electronics, since they can enable pervasive integration of electronic functionalities in all sorts of appliances, their portability and wearability. Here I will report on our recent efforts in making printed polymer electronics (i) ultrathin, to enhance as much as possible conformability, (ii) fast switching, to enable more applications at Radio-Frequencies and (iii) edible, towards electronics systems made with non-toxic, ingestible materials, serving smart pharmaceuticals and food-tagging applications. Mario Caironi obtained his Ph.D. in Information Technology with honours at Politecnico di Milano (Milan, Italy). In 2007 he joined the group of Prof. Sirringhaus at the Cavendish Lab. (Cambridge, UK) as a post-doc, working for 3 years on high resolution printing of downscaled organic transistors and circuits, and on charge transport in high mobility polymers. In 2010 he was appointed as Team Leader at the Center for Nano Science and Technology@PoliMi (CNST) of the Istituto Italiano di Tecnologia (IIT, Milan, Italy). In 2014 he entered the tenure track at the same institution, obtaining tenure in 2019. He is currently interested in solution based high resolution printing techniques for micro-electronic, opto-electronic and thermoelectrics devices, in the device physics of organic semiconductors based field-effect transistors, in biomedical and/or implantable sensors and electronics for the healthcare. He is a 2014 ERC Starting grantee and a 2019 ERC Consolidator grantee.
Session: Invited Session 3 - Chemistry & Materials
Flexible Electronics for Smart Sensor Systems
Eugenio Cantatore
Department of Electrical Engineering, Eindhoven University of Technology,

Flexible large-area electronics based on TFTs is an ideal platform to build smart sensors systems based on the integration of sensing elements, sensor interface circuits, signal processing and data transmission. Depending on the application, matrices or single sensors might be needed, as well as the use of TFTs together with Silicon ICs could be demanded. Applications span a variety of domains in the Internet of Things world: from wearables for the measurement of vital signs and biopotentials, to matrices of physical sensors (e.g. pressure, infrared radiation), to smart sensors integrated in RFID or NFC tags. Designing the architecture and the single circuit blocks for these increasingly more complex systems is a grand challenge due to e.g. the limited performance of flexible TFTs, and the difficulty to interface TFTs with sensors or Silicon Integrated Circuits. An overview of recent achievements in the field of smart flexible sensor systems and a vision for the future of this exciting research domain will be the main focus of this talk. Eugenio Cantatore received his Master’s and Ph.D. Degree in Electrical Engineering from Politecnico di Bari, in 1993 and 1997 respectively. Till 1999 he was fellow at the European Laboratory for Particle Physics (CERN), Geneva. In 1999 he moved to Philips Research, Eindhoven, and in 2007 joined the Eindhoven University of Technology, where he is full professor since 2016. His research interests include the design and characterization of electronic circuits exploiting emerging technologies and the design of ultra-low power micro-systems. He authored or co-authored more than 200 papers in journals and conference proceedings, and 13 patents. He has been active in the Technical Program Committees of ESSDERC, IWASI, ESSCIRC and ISSCC. At ISSCC he has been chair of the Technology Directions subcommittee, Program Chair in 2019 and is presently Conference Vice Chair. He is member at large of the SSCS AdCom, associate editor of the IEEE Transactions on Circuit and Systems I and editor in chief of the IEEE Open Journal of the Solid-State Circuits Society. In 2006 he received the ISSCC Beatrice Winner Award for Editorial Excellence and was nominated in the Scientific American top 50 list. He received the Philips Research Invention Award in 2007, the Best Paper Award from ESSDERC 2012 and the Distinguished Technical Paper Award from ISSCC 2015. He was nominated IEEE Fellow in 2016.
Session: Invited Session 6 - Systems
Development of Printed Electrolyte-Gated Transistors for Biological Sensing Applications
Ta-Ya Chu
National Research Council Canada, Ottawa, Ontario, Canada,

In this talk, the challenges and opportunity of electrolyte-gated field effect transistors (EGFET) will be introduced for the biological sensing applications. Different type electrolyte materials have been applied for EGFET in the last two decades, the state-of-the-art in the application of biosensing will be presented. Proton conducting polymer electrolytes have shown a great potential due to their high ionic conductivity and environmental stability. We have demonstrated a phosphoric acid-PVA proton conducting polymer EGFET with organic semiconductor which achieved a low subthreshould swing of 90 mV/decade with sub 1 V operation voltage and a high ON/OFF ratio of 105. Further development of printing process for the fabrication of printed sweat wristband will be discussed. Dr. Chu has been working as a Research Officer/Scientist at National Research Council Canada since 2008. He has more than twenty years of experience in the field of organic electronics, such as OLED, OPV, OTFT and printable electronics. He has contributed more than fifty publications in peer-reviewed journals and conference proceedings which have been cited more than 3,000 times. Dr. Chu is also an Adjunct Professor in the Department of Materials Science and Engineering at University of Toronto. He also serves as the chair of the IEEE EDS Flexible Electronics and Display Technical Committee and the Canadian Vice-Chair for IEC TC-119 Printed Electronics.
Session: Invited Session 2 - Devices
Flexible Arrays of Printed Devices and Their Use in Wearable Medical Devices
Ana Claudia Arias
University of California, Berkeley,

Fabrication of wearable medical sensors heavily relies on conventional semiconductor vacuum processing. We have adopted the unique manufacturing capabilities of printed electronics and designed wearable medical devices that are soft, lightweight, and skin-like. These soft and conformable sensors significantly improve the signal-to-noise ratio (SNR) by establishing a high-fidelity sensor-skin interface. Over the past 8 years we have used different printing techniques for fabricating wearable medical sensors in two sensing modalities: bioelectronic and biophotonic. In bioelectronic sensing, we have designed and fabricated flexible and inkjet-printed gold electrode arrays which were implemented in a smart bandage for early-detection of pressure ulcers. Recently, the efficacy of the electrodes is demonstrated on conformal surfaces and on the skin to record electrocardiography (ECG) and electromyography (EMG) signals. In biophotonic sensing, we have demonstrated a flexible and printed sensor array composed of organic light-emitting diodes and organic photodiodes, which senses reflected light from tissue to determine the oxygen saturation. We use the reflectance oximeter array beyond the conventional sensing locations. The sensor is implemented to measure oxygen saturation on the forehead with 1.1% mean error and to create 2D oxygenation maps of adult forearms under pressure-cuff–induced ischemia. In addition, we present mathematical models to determine oxygenation in the presence and absence of a pulsatile arterial blood signal. In this talk I will also discuss the challenges of integrating soft sensors with hard silicon-based integrated circuits for wearable health monitoring. Prof. Arias received her PhD in Physics from the University of Cambridge, UK in 2001. Prior to that, she received her master and bachelor degrees in Physics from the Federal University of Paraná in Curitiba, Brazil in 1997 and 1995 respectively. She joined the University of California, Berkeley in January of 2011. Prof. Arias was the Manager of the Printed Electronic Devices Area and a Member of Research Staff at PARC, a Xerox Company. She went to PARC, in 2003, from Plastic Logic in Cambridge, UK where she led the semiconductor group. Her research focuses on the use of electronic materials processed from solution in flexible electronic systems. She uses printing techniques to fabricate flexible large area electronic devices and sensors.
Session: Welcome / Plenary Session 1
Development of a Zn/MnO2Based Flexible Battery
JustOne Crosby1, Himanaga Emani2, Xingzhe Zhang2, Dinesh Maddipatla2, Soma Ahmadi2, Qingliu Wu1, Bradley Bazuin2, Matthew Stoops1, Massood Atashbar2
1Department of Chemical and Paper Engineering, Western Michigan University, Kalamazoo, MI, USA, 2Department of Electrical and Computer Engineering, Western Michigan University, Kalamazoo, MI, USA

A flexible battery based on zinc (anode) and manganese dioxide (MnO2) (cathode) as active materials was fabricated for wearable electronics. Carbon black was used as a conductive additive in the cathode to enhance the conductivity of MnO2. Potassium hydroxide (KOH) is saturated with zinc oxide (ZnO) and used as an electrolyte. A flexible polyethylene terephthalate (PET) substrate was used to coat ink slurries for anode and cathode. Electrochemical performance of the battery was compared with coin-cell within range of 0.8 - 1.2 V. Flexible Zn/MnO2 based battery demonstrated a capacity of 0.25 mAh along with a voltage potential of 1.1 V when discharged at 0.01C. Flexible battery exhibited a higher specific capacity of 80 mAh/g compared to 40 mAh/g for the coin-cell.
Session: Abstract Session 5
A platform perspective for fully-printed integrated circuits
Giorgio Dell'Erba
FLEEP Technologies,

Efforts in the development of printed and flexible devices are now encouraged by the increased maturity of the field of printed electronics. However, demonstrations of complex systems based only on printed or flexible components are still limited. This factor restricts the possibilities for the technology to reach the market, with a cascading effect on the entire supply chain. The main limitations to the development of the whole industry are given by the intrinsic difficulties in the multi-device integration and by the lack of a consolidated technology for the processing of signals coming from sensors, for the regulation and exploitation of energy sources and for the piloting of actuators to provide feedback to the final user. For this reason, there is wide interest in the development of flexible integrated circuits (IC) that allow to exploit the full potential provided by this type of technology. In this context, a platform-based approach is desirable in order to take advantage of the peculiarities of printed electronics and access the sustainable side of this technology. Giorgio Dell'Erba received his MSc degree from Politecnico di Milano (Italy, 2012) in Electronic Engineering with specialization in Electronics for Medicine and Nano-Biotechnology. He then obtained his PhD in Electronics (Italy, 2015) at Politecnico di Milano with a full scholarship from the Italian Institute of Technology. In 2016, he received the Young Innovator Under 35 award from MIT Technology Review Italy. During his postdoctoral studies, Dell'Erba received a Fulbright scholarship to study Entrepreneurship at Santa Clara University Leavy School of Business (California, USA, 2018). During the same period, he was a Visiting Post-Doc at Lawrence Berkeley National Labs (California, USA). In 2019, he founded FLEEP Technologies (FLEEPtech) of which he is currently CEO. Giorgio is a mentor for multiple renowned startup accelerators such as INAM Berlin and Plug And Play Tech Center and is Scout Fellow for Berkeley Skydeck VC.
Session: Invited Session 6 - Systems
Liquid Metal Enabled Soft and Stretchable Electronics
Michael Dickey
NC State University,

Liquid Metals? Usually the term evokes thoughts of mercury (toxic!) or the Terminator (a villain!). Yet, gallium-based liquid metals are often overlooked despite their remarkable properties: melting points below room temperature, water-like viscosity, low-toxicity (unlike Hg), and effectively zero vapor pressure (they don’t evaporate!). They also have, by far, the largest interfacial tension of any liquid at room temperature. Normally small volumes of liquids form spherical or hemi-spherical structures to minimize surface energy. Yet, these liquid metals can be patterned into non-spherical shapes (cones, wires, etc) due to a thin, oxide skin that forms rapidly on its surface. This talk will describe efforts in our research group to harness this oxide to pattern and manipulate metal into shapes—such as wires and particles—that are useful for applications that call for soft and deformable metallic features. It is possible to pattern the metal by injection into microchannels or by direct-write 3D printing at room temperature to form ultra-stretchable wires, deformable antennas, and microelectrodes. It is also possible to remove / deposit the oxide using electrochemistry to manipulate the surface tension of the metal over unprecedented ranges (from the largest tension of any known liquid to near zero) and thereby control the shape and position of the metal for shape reconfigurable devices. This work has implications for soft and stretchable electronics; that is, devices with desirable mechanical properties for human-machine interfacing, soft robotics, and wearable electronics. Michael Dickey received a BS in Chemical Engineering from Georgia Institute of Technology (1999) and a PhD from the University of Texas (2006) under the guidance of Professor Grant Willson. From 2006-2008 he was a post-doctoral fellow in the lab of Professor George Whitesides at Harvard University. He is currently the Camille and Henry Dreyfus Professor in the Department of Chemical & Biomolecular Engineering at NC State University. He completed a sabbatical at Microsoft in 2016. Michael’s research interests include soft matter (liquid metals, gels, polymers) for soft and stretchable device
Session: Invited Session 2 - Devices
A Critical Comparison of Printed Semiconductor Based Thin-Film Transistor Technologies for Small Channel Length Applications
Ananth Dodabalapur
The University of Texas at Austin,

Thin-film transistor (TFTs) channel lengths need to shrink as performance requirements get more demanding for several applications. The switching speed and current drive capability are expected to improve as channel lengths reduce for most field-effect transistors. In many TFTs, contact resistance issues get severe at small channel length. Additionally, the physics of charge transport and basic performance characteristics can change quite substantially at small channel lengths in the range 10 nm – 3 micrometer. We will review these properties for amorphous metal oxide, polymer/organic, and printed single walled carbon nanotube TFTs. Such semiconductors can be deposited from solution by printing. Ananth Dodabalapur received his Ph.D. degree in Electrical Engineering from The University of Texas at Austin in 1990. Between 1990 and 2001 he was with Bell Laboratories, Murray Hill, NJ. He has published more than 250 articles in refereed journals which have resulted in an H Index of more than 90 (Google Scholar), and has 27 issued US patents, which have been cited nearly 2000 times. Since September 2001, he is with The University of Texas at Austin and holds the Motorola Regents Chair in Engineering. His present research includes organic and inorganic thin-film transistors and optoelectronic devices, 2D materials device physics and device chemistry, and flexible thin-film electronics. In 2003, he co-founded OrganicID, a company that is investigating using printable polymer electronics to fabricate low-cost RFID tags for the 13.56 MHz frequency. He was the founding Editor-in-Chief of Flexible and Printed Electronics.
Session: Invited Session 1 - Devices
Organic and inorganic printable electronics materials
Antonio Facchetti
Northwestern University/Flexterra,

In this presentation I will report the most important classes of materials used for the fabrication of opto-electronic devices. Thus, I will start very briefly describing the most common electronic devices such as transistors, diodes, and solar cells. Next, I will describe Next, materials such as the semiconductors, conductors, dielectrics, and other corollary materials will be discussed. Particularly I will focus on the basic chemical structural requirements necessary to achieve the desired electronic or photonic properties. Emphasis will be given to the materials that can be processed by solution methodologies, such as spin-coating, slot-die, ink-jet printing, screen printing, and gravure printing with example of opto-electronic devices achieved by them. I will concluded with the major challenges and opportunities that this research is facing. Antonio Facchetti is a co-founder and currently the Chief Technology Officer of Flexterra Corporation. He is also an Adjunct Professor at Northwester University. He has published more than 520 research articles, 14 book chapters, and holds more than 120 patents (h-index 108). He received the ACS Award for Creative Invention, the Giulio Natta Gold Medal of the Italian Chemical Society, the team IDTechEx Printed Electronics Europe Award, the corporate Flextech Award. He is a Fellow of the European Academy of Sciences, National Academy of Inventors, MRS, AAAS, PMSE, Kavli, and RSC Fellow. He was selected among the "TOP 100 MATERIALS SCIENTISTS OF THE PAST DECADE (2000-2010)" and recognized as a Highly Cited Scientist by Thomson Reuters.
Session: AM Short Course 1: Printed Electronics - Materials, Processes and Devices Presented by OE-A
Improving FHE Interconnection Reliability with Parallel Gap Welding
Tim Frech
EWI -Edison Welding Institute, Columbus, OH, USA

The use of flexible electronics and 3D-printed electronics are both emerging applications in consumer, medical device, and military electronics. With these exciting products, joining of these materials has become a need. Presently, only soldering is used in prototyping and low-volume manufacturing, which is not an ideal process for high-volume manufacturing due to limitations of speed, joint size, and strength. Parallel gap and ultrasonic welding are joining processes that could effectively replace soldering in manufacturing these electronics. Both are relatively fast processes with minimal heat input. Welded joints with these processes would be more reliable, more rugged, and withstand higher temperatures than soldered joints. In this presentation, process data and recommendations will be provided for joining to flex circuits and FHE's. These methods eliminate the need for soldering and provide a higher-speed, lower profile, and lower-cost interconnections for a wide range of electronics products.
Session: Abstract Session 3
Advanced Design Capabilities and Manufacturing Considerations Utilizing Liquid Metal Conductors in Flexible Hybrid Electronics
Mike Hopkins
Liquid Wire, Inc.,

Liquid metal (LM) conductors enhance flexible hybrid electronics (FHEs) in two major ways, additional flexibility and best-in-class stretchability. Durability of as built circuits under heavy flex and stretch cycling is greatly improved. Along with this enhancement come completely new modalities in design and manufacture of a circuit. The key to LMFHE manufacture is the via structure. The via becomes not only the method of generating more complex, multi-layer circuits, but also the hard to soft transition step that connects a soft circuit to the traditional world of connectors, ICs, and solid wiring. We have spent the last few years in generating robust heterogeneous junctions and via systems and characterized them under rigorous physical testing. We have also spent this time exploring creative ways in which soft circuits can be generated by laminate additive manufacture and how these can lead to novel device structures. We have determined design rules for manufacture supporting modular FHE architectures with LMFHE interconnect and via systems that lead to better mechanical and manufacturing outcomes and have metrics that show these performance increases. Dr. Hopkins has worked in the field of soft electronics for four years with Liquid Wire Inc. Primarily operating in the role of lead electronics designer and staff scientist while the company transitioned from LLC to C-corp, and through its successful raising of multimillion dollar series A investment. Through this time Dr. Hopkins has developed many methodologies of sensing with gel phase conductors and manufacturing techniques for application of fluid and gel phase conductors. Working with many designers in the performance apparel industry he has generated many successful prototype products in the flexible hybrid electronics space. Prior to joining Liquid Wire Dr. Hopkins has worked on the design and use of many pieces of scientific equipment. Co-developing three separate near-field scanning optical microscopes with Drs. Andres LaRosa, Rodolfo Hernandez-Rodriguez, Eric Sanchez, and John Freeouf, he developed new tip designs, operation level enhancements and optimizations in signal strengthening for various detection methodologies. Dr. Hopkins has also spent many years in thin film deposition and characterization, building two thermal evaporation system and one sputter deposition system operating at high vacuum, while also using commercial deposition systems including atomic layer deposition. His work a Portland State University culminated with a Ph.D. on the topic of quantum chemistry in magnetic thin film chalcogenides.
Session: Invited Session 4 - Additive Manufacturing
Impact of Diverse Ambient Illuminations on a Flexible Photosensitive Energy Scavenger
Emad Iranmanesh1, Ahmed Rasheed2, Hang Zhou1, Kai Wang3
1School of Electronic and Computer Engineering, Peking University, Shenzhen Graduate School, 518055, Shenzhen , China, 2School of Electrical Engineering and Computer Science, National University of Science and Technology, Islamabad, Pakistan, 3School of Electronics and Information Technology, Sun Yat-Sen University, 510006, Guangzhou , China

This paper details the effect of diverse environmental light conditions on characterization of a piezoelectric transducer biased photosensitive dual-gate thin-film transistor as a dual- mode wearable harvester. It demonstrates that exposure of harvesting module over ambient illuminations effectively decreases the internal resistance of DGTFT and results in peak voltage enhancement along with peak power increment. Ultimately an in-depth experimental analysis of peak power under distinct ambient illuminations shapes a daily usage pattern for further investigation.
Session: Abstract Session 5
Flexible Hybrid Electronics Manufacture - An Overview
Simon Johnson
Centre for Process Innovation,

This short tutorial will present an overview of the techniques and technologies used in the manufacture of flexible hybrid electronic (FHE) circuits. The fundamentals of the technologies will be discussed along with the assembly techniques and we will also consider the types of circuits that can be built with FHE. The benefits of the circuit form will be considered along with the challenges and some solutions. Roll to Roll manufacture of electronics will be discussed to show the approach to scale up for industrial applications. Some case studies will also be used to illustrate many aspects of this exciting technology. Dr Simon Johnson is the Chief Technologist within Electronics at the Centre for Process Innovation in the UK. In his current role Simon acts as a knowledge expert in Printable and Flexible Electronics, supporting strategic and development activities in the business. While at CPI Simon has lead the development of processes for the assembly of hybrid flexible electronic systems including printed sensors, wireless sensor systems and roll to roll circuit design and assembly. In previous roles as an academic at the University of Durham and also in industry, Simon has worked in many aspects of electronics from CMOS IC design and development to electronic systems and software development.
Session: AM Short Course 1: Printed Electronics - Materials, Processes and Devices Presented by OE-A
Flextronics: A Hard Barrier for Flexible Teaching?
Savas Kaya
Ohio University,

As it becomes more accessible and mainstream, flexible electronic devices and integrated systems (or flextronics) technologies present unique challenges for instructors and tremendous opportunities of learning for students on a broad spectrum of engineering subjects. On the one hand lies the significant challenges of arranging, simplifying and presenting very diverse range of properties related to materials (nano-inks, carbon nano-structures, conductive polymers, organic semiconductors, metal-oxide thin-films), substrates (polymers, papers, textile and composites), printing technologies (laser, screen, flexographic, gravure, inkjet, aerosol Jet) and devices (RLC passives, thin-film transistors, antennas, solar cells, OLEDs & displays, supercapacitors, batteries and sensors) as well as virtually unlimited range of applications. On the other hand is the tremendous learning opportunities in reviewing scientific fundamentals, integrated device design and exploring creative solutions with flexible technologies for seniors and graduate students that cannot be found easily in such a comprehensive fashion. On either front, there is a sheer volume of material to be explored and contextualized, which present challenges for all involved. In this tutorial session, we will describe and analyze some of these challenges and opportunities for building a successful course in Flextronics education and propose an example course syllabus based on the best practices as surveyed from reputable institutions around the world. The tutorial is intended for both researchers and educators planning to develop a course in Flextronics as well as students who wishes to develop a wholesome overview of flexible electronics from an educator’s perspective. Savas Kaya (SM'07) received the M.Phil. degree from the University of Cambridge, Cambridge, U.K., in 1994, with a focus on polarization insensitive liquid crystal switches and the Ph.D. degree from the Imperial College of Science, Technology and Medicine, London, U.K., in 1998, with a focus on strained Si quantum wells on vicinal substrates. He was a post-doctoral researcher at the University of Glasgow between 1998 and 2001, carrying out research in transport and scaling in Si/SiGe MOSFETs, and fluctuation phenomena in decanano MOSFETs. He is currently a professor with the Russ College of Engineering at Ohio University, Athens. Besides, flexible electronics and printed sensors, his other interests include transport theory, device modeling and process integration, nanofabrication, nanostructures and nanosensors for flexible electronics integration.
Session: PM Short Course 3: Flextronics: A Hard Barrier for Flexible Teaching?
Flexible Touch Pad on Paper and Cloth by Blue Diode Ablated Laser Induced Graphene
Avinash Kothuru, C. Hanumanth Rao, Sanket Goel
MEMS, Microfluidics and Nanoelectronics (MMNE) Lab, Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Hyderabad, India

In recent year, Graphene has witnessed an increasing demand in diversified domains including in realizing various electronic devices due to its unique electrical and mechanical properties. In place of the conventional cumbersome approaches, recently CO2 laser induced graphene (LIG) on various substrates, like polymers, paper, cloth, have become a reliable alternative to fabricate such devices. Even though, development of LIG zones on diverse substrate and their optimization and implementation has been reported, a process to manifest single-step, cost-effective and scalable LIG based flexible electronic devices remains a challenge. Herein, a novel process has been demonstrated for fabricating LIG based flexible electronic device on paper and cloth using a low-power blue laser. First, a porous filter paper and a cotton cloth were soaked in liquid polyimide and phenolic resin-polyvinyl alcohol (PR-PVA) respectively. Subsequently, a 3D printer, loaded with a 2.8 W blue laser diode, was appropriately ablated to form paper-based LIG (P-LIG) and cloth-based LIG (C-LIG), with desired designs and conductivity values. P-LIG and C-LIG zones provide optimum conductivity values of 198.54 S/m and 22.23 S/m respectively. Finally, P-LIG and C-LIG were integrated with the capacitive touch sensor and microcontroller modules, and display, to employ both the devices as flexible touch sensors.
Session: Abstract Session 6
Solution processable GHz silicon Schottky diodes
Laura Kühnel1, Kevin Neumann2, Fabian Langer1, Daniel Erni2, Roland Schmechel1, Niels Benson1
1Institute of Technology for Nanostructures (NST), Duisburg, Germany, 2General and Theoretical Engineering (ATE), Duisburg, Germany

Printed, flexible electronics are a key component within the Internet-of-Things concept as they exhibit the potential for high-throughput and cost-effective manufacturing. However, due to the limited high frequency performance of current printable electronic materials, solution processable or printable electronic components capable of GHz switching speeds are currently not possible. Our approach to address this need, e.g. for passive chipless RFID technology, and to overcome the discussed material limitation is the use of silicon (Si) and to make it printable. To achieve this, inks based on Si nanoparticles (NP) are used. To enable high frequency operation the deposited NP thin film is transformed into self-organized crystalline µ-cone shaped structures using an excimer laser treatment, with their growth being controlled by parameters such as laser energy density and nanoparticle thin film thickness. Due to the lateral discontinuity of the µ-cones, as well as their small base area, this structure is expected to be mechanically flexible. Further, the Si µ-structures are highly crystalline as substantiated using TEM and µ-Raman analysis and therefore offer great potential for high frequency applications. Embedded into an insulator matrix, these µ-cones are used for the realization of a novel type of Schottky diode. This diode is at least working up to 4 GHz, putting printable high frequency electronics within reach.
Session: Abstract Session 3
Process-Properties-Performance Interaction of Additively Printed Flexible Circuits with Surface Mount Components
Pradeep Lall

Pradeep Lall
Auburn University,

A number of processes for additive printed electronics have emerged including aerosol-jet printing, inkjet printing, dispense-on-demand printing, screen-printing, gravure printing amongst others. Additive printed technologies allow for design of manufacture of electronics in exceedingly small lot-sizes owing to the ability to print parts on demand. Technologies such as aerosol-jet, ink-jet printing, and dispense-on-demand printing allow for manufacture of non-planar components without the need for planar build-up often used in traditional methods presently used for electronics design and fabrication. In this paper, the interaction of process parameters with the electrical properties, mechanical properties, and the realized performance of ink-jet printed substrates and direct-write substrates has been studied. The frequency response of additively printed circuits has been compared with conventional circuits. The shear load to failure, and resistivity of the printed line have been studied to quantify the performance of the printed lines. Process parameters studied include droplet volume, on-off voltage, phase width, on-off time, print speed, resolution, ink pressure, platen temperature, standoff height. Better understanding of the effect of each process parameter in the printed lines will allow users to select appropriate process parameters for design functional performance. In addition, the development of process-property relationships will provide visibility into the critical parameters, which require added level of attention for process-control. Process parameter drift over a long production run may be important for a high-volume production environment. The effect on the print process may be in the form of line consistency, and resistance – both of which have been quantified in this study through the quantification of process-capability for z-axis interconnects. Data is presented on 2-layer and 5-layer substrates. Pradeep Lall is the MacFarlane Endowed Distinguished Professor with the Department of Mechanical Engineering and Director of the NSF-CAVE3 Electronics Research Center at Auburn University. He holds Joint Courtesy Appointments in the Department of Electrical and Computer Engineering and the Department of Finance. He is a member of the technical-council, academic co-lead of the asset-monitoring TWG of NextFlex Manufacturing Institute. He is the author and co-author of 2-books, 14 book chapters, and over 700 journal and conference papers in the field of electronics reliability, safety, energy efficiency, and survivability. Dr. Lall is a fellow of the ASME, fellow of the IEEE, a Fellow of NextFlex Manufacturing Institute, and a Fellow of the Alabama Academy of Science. He is recipient of the Auburn Research and Economic Development Advisory Board Award for Advancement of Research and Scholarship Achievement, IEEE Sustained Outstanding Technical Contributions Award, National Science Foundation’s Alex Schwarzkopf Prize for Technology Innovation, Alabama Academy of Science’s Wright A. Gardner Award, IEEE Exceptional Technical Achievement Award, ASME-EPPD Applied Mechanics Award, SMTA’s Member of Technical Distinction Award, Auburn University’s Creative Research and Scholarship Award, SEC Faculty Achievement Award, Samuel Ginn College of Engineering Senior Faculty Research Award, Three-Motorola Outstanding Innovation Awards, Five-Motorola Engineering Awards, and over Thirty Best-Paper Awards at national and international conferences.
Session: Invited Session 4 - Additive Manufacturing
Towards GHz flexible organic electronics
Karl Leo
Dresden Integrated Center for Applied Physics and Photonics (IAPP), Technische Universität Dresden,

Karl Leo obtained the Diplomphysiker degree from the University of Freiburg in 1985, working with Adolf Goetzberger at the Fraunhofer-Institut für Solare Energiesysteme. In 1988, he obtained the PhD degree from the University of Stuttgart for a PhD thesis performed at the Max-Planck-Institut für Festkörperforschung in Stuttgart under supervision of Hans Queisser. From 1989 to 1991, he was postdoc at AT&T Bell Laboratories in Holmdel, NJ, U.S.A. From 1991 to 1993, he was with the Rheinisch-Westfälische Technische Hochschule (RWTH) in Aachen, Germany. Since 1993, he is full professor of optoelectronics at the Technische Universität Dresden. His main interests are novel semiconductor systems like semiconducting organic thin films; with special emphasis to understand basics device principles and the optical response. His work was recognized by a number of awards, including: Otto-Hahn-Medaille (1989), Bennigsen-Förder-Preis (1991), Leibniz-Award (2002), award of the Berlin-Brandenburg Academy (2002), Manfred-von-Ardenne-Preis (2006), Zukunftspreis of the German president (2011), Rudolf-Jäckel-Prize (2012), Dr. techn. h.c. of the University of Southern Denmark (2013), and Technology Transfer Prize of the DPG (2016). He is cofounder of several companies, including Novaled GmbH and Heliatek GmbH.
Session: Invited Session 6 - Systems
Low-Resistance Screen-Printed Nanoparticle Ink Tracks for High-Current Applications
Xiaotian Li, Henrik Andersson, Johan Sidén
Mittuniversitetet, Sundsvall, Sweden

Nanoparticle (NP) conductive inks can achieve a lower resistivity than flake inks due to agglomeration and merging of the NPs during the sintering process. However, it is challenging to print NP conductive inks with sufficient thickness to achieve a low resistance, which limits their use in high-current applications. In this paper, we present low resistance tracks fabricated by screen printing a NP Ag ink and investigate the possibilities for the tracks to be used for high-current applications. DC current carrying capacity tests are performed to these tracks. The results show that the printed tracks have achieved a significant lower resistance than inkjet-printed NP Ag ink tracks and possess potentials to be used in power electronic systems.
Session: Abstract Session 6
Additive Manufacturing of Geometrically-Complex Electronics and Electromagnetics
Eric MacDonald
Additive Printing,

3D printing has been historically relegated to fabricating conceptual models and prototypes; however, increasingly, research is now focusing on fabricating functional end-use products. As patents for 3D printing expire, new low-cost desktop systems are being adopted more widely and this trend is leading to a diversity of new products, processes and available materials. However, currently the technology is generally confined to fabricating single material static structures. For additively manufactured products to be economically meaningful, additional functionalities are required to be incorporated in terms of electronic, electromechanical, electromagnetic, thermodynamic, chemical and optical content. By interrupting the printing processes and employing complementary manufacturing, additional functional content can be included in mass-customized complex structures. The two-hour short course will provide a comprehensive overview of the full taxonomy of additive manufacturing processes as defined by the ISO/ASTM 52900 standard. Each of the seven additive manufacturing processes will be described in terms of both operation and in the context of benefits and challenges for electronics and electromagnetics. A diversity of case studies will be provided highlighting the profound benefits of fabricating electronics with the design freedom, mass customization and geometrical-complexity that additive manufacturing brings to bear. Eric MacDonald, Ph.D. is a professor of mechanical at the University of Texas at El Paso and engaged in the W.M. Keck Center for 3D Innovation. Dr. MacDonald received his doctoral (2002) degree in Electrical and Computer Engineering from the University of Texas at Austin. He worked in industry for 12 years at IBM and Motorola and subsequently co-founded a start-up specializing in CAD software and the startup was acquired by a firm in Silicon Valley. Dr. MacDonald held faculty fellowships at NASA's Jet Propulsion Laboratory, US Navy Research and was awarded a US State Department Fulbright Fellowship in South America. His research interests include 3D printed multi-functional applications and process monitoring in additive manufacturing with instrumentation and computer vision for improved quality and yield. As a co-founding editor of the Elsevier journal Additive Manufacturing, MacDonald has help direct the journal to have the highest impact factor among all academic journals worldwide in manufacturing. Recent projects include 3D printing of structures such as nano satellites with structurally-embedded electronics (one of which was launched into Low Earth Orbit in 2013 and a replica of which was on display at the London Museum of Science). He has over 100 peer-reviewed publications, dozens of patents (one of which was licensed by Sony and Toshiba from IBM). He is a member of ASME, ASEE, senior member of IEEE and a registered Professional Engineer in the USA state of Texas.
Session: PM Short Course 4: Additive Manufacturing of Geometrically-Complex Electronics and Electromagnetics
Highly Compliant Flexible and Printable Magnetoelectronics for Human-Machine Interfaces and Soft Robotics
Denys Makarov
Helmholtz-Zentrum Dresden-Rossendorf,

Motion sensing is the primary task in numerous disciplines including industrial robotics, prosthetics, virtual and augmented reality appliances. In rigid electronics, rotations, displacements and vibrations are typically monitored using magnetic field sensors. Here, we will discuss the fabrication of flexible, stretchable and printable magnetoelectronic devices. The technology platform relies on high-performance magnetoresistive and Hall effect sensors deposited or printed on ultrathin polymeric foils. These skin compliant flexible and printable magnetosensitive elements enable touchless interactivity with our surroundings based on the interaction with magnetic fields, which is relevant for smart skins, soft robotics and human-machine interfaces. Denys Makarov obtained his Master Degree (2005) at the Taras Shevchenko National University of Kyiv in Ukraine, followed by a Ph.D. (2008) from the University of Konstanz in Germany. Until September 2015, he was group leader of “Magnetic Nanomembranes” at the Leibniz IFW Dresden. Since October 2015, Denys Makarov is a member of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and currently assumes a position of the head of department “Intelligent materials and systems” and leads the Helmholtz Innovation Lab FlexiSens. With his activities, Denys Makarov made a decisive contribution to the development of the field of curvilinear magnetism and stimulated research on spintronics on flexible, bendable and stretchable surfaces. Mechanically flexible, printable and skin compliant magnetic field sensors enable new application scenarios for human-machine interfaces, soft robotics, eMobility and medicine. The development of this novel research field is supported in the frame of major national and European projects. Denys Makarov a Senior Member of the IEEE and a Fellow of the Young Academy of Europe.
Session: Invited Session 5 - Devices & Systems
Recent Advances in Flexible Electrophoretic Display Technology Including Full Color Reflective Displays
Michael McCreary
E Ink Corporation,

Electrophoretic display technology (EPD) is intrinsically flexible. New advancements have been recently achieved in foldable full color EPD including front lights as well as rollable B&W EPD. The importance of EPD to education and health markets will be discussed including the stress put on hospital communication systems by COVID. Dr. Michael McCreary is responsible for expanding the portfolio of advanced technologies at E Ink to help enabling new generations of novel electronic paper and other products. Dr. McCreary is a veteran of the imaging industry with a 47 year career that spans chemical photographic image capture, digital chip image capture, and digital display imaging. He also currently serves on the Governing Board of the SEMI FlexTech Alliance Council. Prior to joining E Ink in 2000, McCreary held a number of leadership positions with the Eastman Kodak Company, the last one being General Manager of the Microelectronics Technology Division which developed world record high performance solid-state image sensors including the CCDs used in high quality Nikon and Canon professional cameras. McCreary earned his Ph.D. in Physical Organic Chemistry from the Massachusetts Institute of Technology and completed further studies in solid state and device physics at the Rochester Institute of Technology. Dr. McCreary has been a frequent invited speaker at many international technical symposia and is named co-inventor on 92 patents worldwide.
Session: Invited Session 2 - Devices
A sustainable industrial Silicone based substrate as well as circular platform to drive FHE manufacturing and supply chain for wearable, e-skin applications
Anupam Mukherjee1,2, Padmanabh Pundrikaksha Pancham1,3, Hao-Yang Yang1
1General Silicones Co., Ltd., Hsinchu, Taiwan, 2Department of EECS, National Yang Ming Chiao Tung University , Hsinchu, Taiwan, 3Department of Nano Engineering and Micro systems, National Tsing Hua University, Hsinchu, Taiwan

Transition from linear to circular economy to have a sustainable ecosystem is now prevailing in almost every sector including Flexible Hybrid Electronics. Researchers, scientists and stakeholders are putting continuous efforts in order to have sustainable solutions to support circular economy. In order to support Flexible Hybrid Electronics in a sustainable manner, General Silicones with its decades of experience developed a sustainable industrial silicone-based substrate that not only possess excellent chemical and mechanical properties but also removing the drawback of low surface energy of silicone causing adhesion, bonding and printing issues, it can act as innovative sustainable platform to design printed and flexible electronics with unmet possibilities.
Session: Abstract Session 1
Printed Electrochemical Biosensors for Medical Diagnostics
Giorgio Mutinati
AIT Austrian Institute of Technology,

The decentralization of the health care system, driven by the demographic change, creates a strong demand for sustainable high volume and low-cost biosensors that enable molecular diagnostics outside of laboratories. At present, non-invasive point-of-care rapid tests are mostly available in the form of single-use test strips based on a colorimetric readout. The reading of these test strips is strongly influenced by subjective visual perception and the results are, therefore, hardly reproducible and only qualitative. An important exception are electrochemical glucose sensors, which are successfully on the market for several years now. However, they require the diabetic patients to prick their finger and are not used for continuous glucose monitoring. Printing technologies play a key role to overcome these limitations by enabling: i) the use of cost-effective substrates and materials, ii) the effective manufacturing of biosensors using roll-to-roll processes, iii) the use of digital technologies such as inkjet printing to print specifically formulated bio-inks for the sensor surface functionalization, iv) the integration of discrete microchip and printed components such as antennas and batteries for the processing and wireless transfer of measurement data. Making use of these possibilities, the printed biosensors, which are in development now, can be used either as single- use quantitative tests or as monitoring device integrated in wearables. This short course will give an overview about the printed biosensors on the market and in development. Particular attention will be given to the novel applications, the involved printing technologies and the development work done on this topic at AIT Austrian Institute of Technology. Giorgio C. MUTINATI, PhD, after his degree in physics, specialized in micro- and nanotechnology and solid state electronics. After seven years at the R&D departments of semiconductor industries, he joined AIT Austrian Institute of Technology in 2010. His research activities as senior research engineer and project manager focus on printing technologies for the realization of electrochemical biosensors.also in industry, Simon has worked in many aspects of electronics from CMOS IC design and development to electronic systems and software development.
Session: AM Short Course 1: Printed Electronics - Materials, Processes and Devices Presented by OE-A
Flexible Piezoelectric Ultrasonic Transducers Based on Thin-Film Technology: from technology to driving methodologies
Kris Myny
imec, Heverlee, Belgium,

Mid-air ultrasound applications such as vibrotactile feedback and gesture recognition have recently gained traction in the domain of human-machine interaction (HMI) [1]. The ability to integrate flexible ultrasound transducers arrays to various surfaces presents an opportunity to enable non-contact HMI applications, which is becoming increasingly relevant given the recent COVID-19 pandemic. I.e. mitigating pathogenic cross-infection from touching surfaces. Interactive applications which can be enhanced using haptic feedback and/or gesture control such as virtual or augmented reality and telepresence are also foreseen. In order to enable those applications, we will discuss the piezoelectric ultrasound micromachined transducers (pMUTs) that we have developed using thin-film technology processes. These polymer-based pMUTs have the capability to be directly fabricated on flexible thin-film substrates, with the ability to be monolithically integrated with thin-film transistors (TFTs) as those used in the display industry. In the next section, we will discuss the modeling and driving of air-coupled pMUTs from electrical to acoustical simulations [2]. Driving these pMUT arrays to attain a high acoustic pressure field poses significant challenges in terms of power consumption and efficiency. Advanced charge recycling is introduced to tackle these challenges and reduce the required power consumption to drive pMUT arrays [3]. In addition, the monolithic integration of these pMUT arrays with TFT drivers introduces new challenges compared to a silicon-based solution. In this talk we elaborate upon the complexities to design driving circuits for pMUT arrays. Finally, we will discuss the direction and future developments of the thin-film ultrasound transducer technology, which includes the investigation of alternative piezoelectric materials, pMUT array topologies and driving architectures to improve efficiency and performance.This work is supported by the FWO grant of HAPPY: haptic feedback the next step in smart interfacing - S004418N. Kris Myny received his PhD degree in electrical engineering from the KU Leuven, Leuven, Belgium, in 2013. He is now a Principal Member of Technical Staff and R&D Team Leader at imec, and part-time professor at KU Leuven. He specializes in circuit design for flexible thin-film transistor applications. His work has been published in numerous international journals and conferences, including Nature Electronics and several ISSCC contributions. He was listed as one of Belgium’s top tech pioneers by the business newspaper De Tijd and received in 2018 the European Young Researcher Award for design on thin-film electronics. In 2016 he also received a prestigious ERC Starting Grant from the European Commission to enable breakthrough research in thin-film transistor circuits (FLICs). He is now a member of the Young Academy of Belgium between 2019-2024. He also serves as track chair of the FLEPs conference.
Session: Invited Session 1 - Devices
Recycled Carbon-based Strain Sensors: An Ecofriendly Approach using Char and Coconut Oil.
Hugo de S. Oliveira, Federica Catania, Cantarella Giuseppe, Baratieri Marco, Vittoria Benedetti, Niko Münzenrieder
Free University of Bozen-Bolzano, Bolzano, Italy

Bio-compatible high stretchable strain sensors can be applied in several areas ranging from engineering to medical applications. Among many efforts in developing new sensors, there is a growing demand for eco-friendly devices that presents a minimum environmental impact with a low cost. This work deals with the development and analysis of a biocompatible, eco-friendly, and unexpensive strain sensor, easily manufacturable, consisting of natural coconut oil, and recycled char obtained from the waste of a gasifying process. The results demonstrate an average gauge factor of (26.62 ± 17.03), with a linear response until 80% strain, higher hysteresis occurring between strain values of 25% 40% and a stable and reliable response after 250 stretch/release cycles.
Session: Abstract Session 1
Strain Sensing Graphene Functionalized PET Films based on a Facile Dip Coating Approach
Ekin Asim Ozek1, Melih Can Tasdelen1, Sercan Tanyeli1, Murat Kaya Yapici1,2,3
1Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey, 2Sabanci University Nanotechnology Research Center, Istanbul, Turkey, 3Department of Electrical Engineering, University of Washington, Seattle, WA, USA

Strain sensing is crucial in emerging fields such as artificial/virtual reality applications, Internet-of-Things, and smart wearable devices. Strain sensors for the flexible applications are required to be reliable, structurally sound, and cost-effective for both small and vast fabrication batches. It is a challenging task to meet all the requirements yet reduced graphene oxide films show adequate coating on highly accessible substrates and provide proper figure of merits in terms of piezoresistive strain sensing. In this paper, high throughput single step coating of graphene oxide on flexible substrate and single step material functionalization method is presented for reduced graphene oxide based piezoresistive strain sensing on PET substrate. Physically patterned rGO/PET strain sensors are composed of 2 mm line width along a U-shaped 50 mm outline. Proposed rGO/PET film quality for sensor application was verified by Raman spectroscopy. Operation of the reduced graphene oxide based piezoresistive strain sensor is demonstrated to be repeatable via continuous cyclic bending tests.
Session: Abstract Session 4
2cm diameter Antenna & Sharp Multi-threshold Detection Thin-film RFID Tags on Flexible substrate
NIKOLAS PAPADOPOULOS1, Firat Tankut1, Babak Kazemi Esfeh1, Marc Ameys1, Florian De Roose1, Bart Aerts1, Steve Smout1, Myriam Willegems1, Raf Appeltans1, Kris Myny1,2
1imec, Heverlee, Belgium, 2Leuven University, Leuven, Belgium

RFID tags are embedded in everyday objects providing extra functionalities and aiming to connect them to the cloud. Miniaturization of flexible RFID tags enables the integration into smaller everyday health, entertainment, food related objects, besides enhancing security and decreasing the cost. In addition, external sensor integration and readout enable new applications for the sensor tags. In this paper a miniaturized 2cm (1€ coin size) diameter antenna is combined with a flexible InGaZnO thin-film RFID chip operating at 3V and transmitting data at 7.3kHz. Moreover, the sharp threshold detection of a resistive temperature sensor is demonstrated using the same technology, enabling multi-threshold detection on flexible and ultrathin (< 15μm) substrates.
Session: Abstract Session 3
Organic Bioelectronics: Next Generation Point-of-Care Sensors
Anna-Maria Pappa
University of Cambridge,

The development of micro-electronic devices/chips that bridge the gap between the rigidity of traditional electronics with the soft mechanics of biological systems is highly desirable. The emergence of highly conjugated polymers has indeed opened up exciting directions in biomedical research including point-of-care diagnostics. With the ultimate goal of fully integrated wearable sensors combined with IoT, and that of autonomous at-home diagnostic tests, organic bioelectronic technologies have been heavily explored the past decade resulting in novel device configurations. Multiplexing capability, ability to adopt to complex performance requirements in biological fluids, sensitivity, stability, literal flexibility and compatibility with large-area processes are only some of the merits of conjugated polymers for point of care diagnostics. This talk will summarize our recent efforts on developing biosensors for health monitoring, on rigid and flexible substrates showcasing the potential of conjugated polymers towards next generation point of care sensors. Anna-Maria Pappa is an Oppenheimer Research Fellow in the Department of Chemical Engineering and Biotechnology at the University of Cambridge. She is also a research Fellow in Pembroke College in Cambridge. She holds a PhD in Bioelectronics from Ecole Mines de Saint-Étienne, France, where she held a Marie Curie fellowship. She has been awarded the L’Oreal UNESCO Science fellowship (2017) and has been included in the Under 35 Young Innovators list by the MIT Technology Review for 2019. Her research combines microelectronics with biological models for next generation in vitro assays.
Session: Invited Session 3 - Chemistry & Materials
Optimizing Design and Fabrication of Flexible Hybrid Electronics for Medical and Industrial Applications
Mark Poliks
State University of New York at Binghamton,

Mark D. Poliks is a SUNY Distinguished Professor of Engineering and Empire Innovation Professor of Engineering in Systems Science and Industrial Engineering and Materials Science and Engineering at the State University of New York at Binghamton. He is director of the Center for Advanced Microelectronics Manufacturing (CAMM), a New York State Center of Advanced Technology and home to the New York Node of NextFlex. He serves as Chair of the Smart Energy Transdisciplinary Area of Excellence at the Binghamton campus. His research is in the areas of industry relevant topics that include: high performance electronics packaging, flexible hybrid electronics, medical and industrial sensors, printed RF components, materials, processing, aerosol jet printing, roll-to-roll manufacturing, in-line quality control and reliability of electronics. He is the recipient of the SUNY Chancellor’s Award for Excellence in Research. He received FLEXI awards for leadership in Technology and Education from the FlexTech Alliance in 2009 and 2019. He has authored over one hundred fifty technical papers and holds forty-eight US patents. He was the General Chair of the 69th IEEE ECTC and serves as a IEEE Electronics Packaging Society Distinguished Lecturer.
Session: Invited Session 5 - Devices & Systems
Flexible, biocompatible, and ridged silicone elastomers based robust sandwich-type triboelectric nano-generator
Raheel Riaz1,3, Bhaskar Dudem2, Martina Costa Angeli1, Ali Douaki1, Mukhtar Ahmad1, Mattia Petrelli1, Abraham Mejia-Aguilar3, Roberto Monsorno3, S. Ravi P Silva2, Paolo Lugli1, Luisa Petti1
1Sensing Technologies Lab, Free University of Bolzano, Bolzano, Italy, 2Advanced Technology Institute, University of Surrey, Surrey, United Kingdom, 3Center for Sensing Solutions, Eurac Research, Bolzano, Italy

Abstract: Energy harvesting from ambient environmental resources has gained a great attention to power various portable electronics. Among the available renewable resources, it is worth mentioning devices harvesting solar, biochemical, thermal, and mechanical energy. Especially, mechanical energy is abundantly available in our daily life and can be significantly harvested through piezo- and tribo-electric energy harvesters. Triboelectric nanogenerators (TENG) harvesting mechanical energy from human body movements are especially attractive due to its easy adaptation and availability of vast variety of materials. Contact electrification and electrostatic induction are the basic principles behind the energy generation in TENG. Several studies have been done to enhance the output performance of TENG by surface and structural alterations. In this work, a flexible sandwich-type TENG (FS-TENG) based on ridged and biocompatible silicone elastomers and thermoplastic polyurethane has been proposed. The device consists of two nanogenerators stacked together. The interlocking ridged structure and dual nanogenerator architecture provide increased surface area and hence enhanced output. The proposed FS-TENG exhibit open-circuit voltages and maximum power density of ~80 volts and 0.35 mW/cm2, respectively. This preliminary performance already makes the device extremely promising to power low energy smart wearable devices, as well as to monitor pressure in bespoke biomedical applications. Keywords: Energy harvesters, triboelectric nanogenerators, contact electrification, smart wearables
Session: Abstract Session 5
Organic Electrochemical Transistors for Bioelectronics
Jonathan Rivnay
Northwestern University,

Organic electrochemical transistors (OECTs) have gained considerable interest for applications in bioelectronics, power electronics, and neuromorphic computing. Their defining characteristic is the bulk modulation of channel conductance owing to the facile penetration of ions into the (semi)conducting polymer channel. These active channel materials, based on mixed ionic-electronic conducting polymers, can be readily adapted for use in biological settings, readily swell, and provide favorable mechanical properties for bio-interfacing. Their bulk transport properties and processability readily enable flexible, free standing devices, and unique form factors. In the first part of my talk, I will focus on OECT materials design for enhanced sensing characteristics. Synthetic design and processing can yield high performance mixed conductors with large volumetric capacitance and electronic mobility, and OECTs with high transconductance and steep subthreshold switching characteristics for low power sensing. By tailoring ionic transport and trapping characteristics, a range of applications can be targeted. I will then discuss how such materials design enables the development of devices and simple circuits comprised of OECTs that can impart added functionality to sensing nodes and may ease the burden on back end electronics for signal processing. I highlight recent efforts towards compact preamplification schemes and non-volatile devices for synaptic circuits. These efforts demonstrate promise and potential barriers for electrochemical transistors to address critical needs in bioelectronic interfacing. Jonathan earned his B.Sc. in 2006 from Cornell University (Ithaca, NY). He then moved to Stanford University (Stanford, CA) where he earned a M.Sc. and Ph.D. in Materials Science and Engineering studying the structure and electronic transport properties of organic electronic materials. In 2012, he joined the Department of Bioelectronics at the Ecole des Mines de Saint-Etienne in France as a Marie Curie post-doctoral fellow, working on conducting polymer-based devices for bioelectronics. Jonathan spent 2015-2016 as a member of the research staff in the Printed Electronics group at the Palo Alto Research Center (Palo Alto, CA) before joining the Department of Biomedical Engineering at Northwestern University in 2017. He is a recipient of an NSF CAREER award, ONR Young Investigator award, and has been named an Alfred P. Sloan Research Fellow, and MRS Outstanding Early Career Investigator.
Session: Plenary Session 2
Flexible Multi-Modal Capacitive Sensors with Polyurethane Foam Dielectrics for Wearables
Akanksha Rohit, Savas Kaya
School of EE&CS, Ohio University, Athens, OH, USA

We present on the design of highly-sensitive capacitive sensors using conductive textile electrodes and polyurethane (PU) foams as the dielectric layer for wearable sensing applications. Previous works involve complex processes in the fabrication of flexible, stretchable, and composite dielectrics using additional fillers or microstructures. In this work, we demonstrate a simple and cost-effective fabrication technique using polyurethane foam as the dielectric material to form capacitive sensors that are sensitive to stretching, bending and pressure. The magnitude of change in capacitance (10-60%) is increased due to the combined effect of micropores in the dielectric foam and the air gaps at the interface between the textile electrodes and dielectric layer. With the use of microporous PU foam, the change in capacitance under a mechanical load is not only due to the change in the thickness of the dielectric layer but also due to the change in the relative permittivity. Hence the proposed textile capacitive sensors can capture critical information when deployed in different locations on the body demonstrated via a shoe insert, speech detection, breathing and heart rate monitoring.
Session: Abstract Session 2
Vital Sign Monitoring via Flexible Capacitive Sensors:A Comparative Study
Akanksha Rohit, Talha F Canan, Savas Kaya
School of EE&CS, Ohio University, Athens, OH, USA

We present a comparative study on flexible capacitive sensors using three different mechanisms for vital sign monitoring. To record arterial pulse and respiration rate, sensors with a parallel-plate structure and engineered dielectrics with piezoelectric (BTO, PVDF-TrFE) fillers, polyurethane foam or triboelectric frictional layers are explored in this work. The sensitivity of the sensors with alternative mechanisms are compared by placing them on different locations on the body (wrist, neck and suprasternal notch). It is found that PU foam-based sensor is most sensitive option in terms of location and spectral content. Collectively, these sensors can be used in a multimodal patch developed for monitoring respiratory health as well as other abnormalities via sensor fusion.
Session: Abstract Session 2
IMSE Technology for Smart Molded Structures - Technology Verification
Outi Rusanen

This short course is a continuation to Dr. Antti Keränen’s short course on IMSE Technology. It explains why and how the company verifies electronics components and surface mounting adhesives. It has also results from reliability testing. The short course is divided into three parts. The first part describes the verification process, electrical component and surface mounting adhesive verification are discussed in more detail. Many of the packages and surface mounting adhesives, optimized for conventional electronics, can be used with IMSE technology. However, their suitability needs to be verified because conventional electronics does not include the temperature and pressure exposures from thermoforming and injection molding processes. One of the IMSE application areas is automotive and the OEMs have stringent reliability requirements. Before IMSE product validation in automotive use cases, TactoTek has already verified the technology. The second explains the reliability test definition for technology verification. The third part shows results from IMSE verification and product validation testing. The results are from technology verification platforms as well as from demonstrator and customer products. We present reliability testing results together with root cause analysis. Dr. Outi Rusanen received her MSc, Lic. Sc. and D. Sc (Tech.) degrees in electrical engineering from the University of Oulu, Finland in 1988, 1998 and 2000, respectively. She currently works as Principal Interconnection Specialist in the Research and Development Team at TactoTek. Dr Rusanen has 30 years’ experience with electronics interconnections and reliability. She has previously worked at Huawei Finland, Nokia Mobile Phones and Technical Research Centre of Finland (VTT). Dr Rusanen has co-authored about 60 journal and conference papers.
Session: AM Short Course 2: Printed Electronics for Automotive Applications Presented by OE-A
Low Cost Social Distancing Alerting Wristband Device
Souparnika K S, R Nehha Mariam, Sreya Jayan, Hridya Harikumar, Shruti , Vasant Joseph
School of Engineering, Cochin University of Science and Technology, Ernakulam, India

Covid-19 pandemic is ravaging the world and the humankind is facing one of the toughest challenge of this century. The main requirement is to stay safe. According to the Covid-19 protocol, a healthy person who is adjacent to an infected person for more than 15 minutes have a very high chance to get infected. Body temperature more than the normal temperature is one of the symptom of the symbiotic Covid-19 infected person. This paper presents an idea to design a low cost affordable wrist band which alerts the user if a person with higher body temperature is in his/her proximity. Simple component like thermopile temperature sensor, amplifier, monostable multivibrator and LEDs are used to design this wrist band. The paper discusses about the outline circuit in order to achieve this, which can be used by all people.
Session: Abstract Session 2
Printed Low-Voltage Crossbar-PUF for Identification
Alexander Scholz1,4, Lukas Zimmermann3, Axel Sikora2,3, Mehdi B. Tahoori5, Jasmin Aghassi-Hagmann1,4
1Institute for Applied Research, Offenburg University of Applied Sciences, Offenburg, Germany, 2Institute of Reliable Embedded Systems and Communication Electronics, Offenburg University of Applied Sciences , Offenburg, Germany, 3Hahn-Schickard-Gesellschaft f¨ur angewandte Forschung, Villingen-Schwenningen, Germany, 4Institute of Nanotechnology, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, 5Chair of Dependable Nano Computing, Karlsruhe Institute of Technology , Karlsruhe, Germany

Abstract: Physically unclonable functions (PUFs) present a non-volatile, hardware-based security primitive, which can be used for identification tasks. A PUF is capable to generate a unique response based on a system's intrinsic variations, which are introduced during manufacturing. Printed electronics (PE) offers, due to the high amount of possibilities in utilizable substrates, materials, and fabrication methods an interesting foundation for hardware-based security. Furthermore, non-impact printing technology such as inkjet-printing offers the capability of decentralized split-manufacturing of the intrinsic variation source, namely the PUF core, which can be later attached or combined with a silicon-based readout electronic preventing initial readout of the identifier by third parties before deployment. Additionally, the full system can be printed once inkjet-printing technology further matures. The presented work focuses on a PUF in a printed crossbar architecture, incorporating an 8x8-cells crossbar, which can generate a 32-bit wide unique response. Crossbars are of special interest due to their relatively simple fabrication and wiring concept. The cells are realized by diode-connected electrolyte-gated thin-film transistors (EGTs), which are capable to operate at low voltages (< 1.5V). A holistic, simulation-based approach is used to incorporate material-based specific constraints, which influence PUF performance. This allows to predict PUF architecture applicability on an upscaled system. Therefore, PUF metrics such as, uniqueness, reliability, bit aliasing and uniformity are evaluated. The results obtained from printed crossbar PUFs show almost ideal uniqueness of 49.43 %, making it highly suitable for identification tasks. As a proof of concept, a 2x2-cells diode-connected printed crossbar is fabricated and experimentally verified.
Session: Abstract Session 6
Stacked 1D Tellurium Nanowires/Paper based Pressure Sensor with Laser Assisted Patterned PDMS Encapsulation
Venkatarao Selamneni, Parikshit Sahatiya
Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, India

In the recent years, research on wearable electronic sensors including strain sensors, pressure sensor, photodetectors based on nanomaterials has been significantly increased. Till now, various types of pressure sensors have been developed to monitor and detect applied force/pressure based on piezoelectric, piezoresistive, triboelectric and capacitive sensing mechanisms. Especially, piezoresistive pressure sensors have been widely studied due to advantages of simple device structure, cost-effective fabrication procedure. In flexible and wearable electronics field, substrate plays a key role. Due to light-weight, biodegradability, cost-effective and high flexibility, research on paper-based electronics called 'papertronics' tremendously increased for applications like pressure sensors, strain sensors, and photodetectors. This work demonstrates the fabrication of flexible, wearable, and cost-effective piezoresistive pressure sensor based on one dimensional (1D) tellurium nanowires (Te-NWs) deposited on cellulose paper substrates. Te-NWs synthesized by a facile solution process method using sodium tellurite (Na2TeO3) with PVP as surfactant and N2H4 as reducing agent. The device is prepared by stacking three Te-NWs/ coated papers and made contacts on top and bottom. To improve the flexibility and sensitivity of the device, fabricated device is encapsulated in polydimethylsiloxane (PDMS) films with micropyramid structures prepared using laser engraved acrylic mould. Fabricated pressure sensor exhibited a sensitivity of ~ 4.17 kPa-1 for the range 500 Pa to 2.5 kPa and ~ 1.42 kPa-1 for > 2.5 kPa. Furthermore, the device was tested for 1500 continuous cycles and negligible change in the device performance was observed. Successful fabrication of Te-NWs/paper based pressure shows significant potential for real-time applications in personal health monitoring and human-machine interactions.
Session: Abstract Session 6
Direct-band gap, solution-processed 2D layered perovskites for flexible photodetectors
Mohin Sharma1, Ridwan F. Hossain1, Anupama B. Kaul1,2
1Department of Electrical Engineering, PACCAR Technology Institute, University of North Texas, Denton, TX, USA, 2Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA

The two-dimensional (2D) halide perovskites have recently drawn significant interest due to their tunable optoelectronic properties and high-power conversion efficiencies in photovoltaic applications. Here we present the synthesis of the solution processed 2D layered organo-halide (CH3(CH2)3NH3)2(CH3NH3)n-1PbnI3n+1 (n = 4) perovskites and the fabrication of heterostructure flexible photodetector (PD) devices on polyimide (PI) substrates using the additively manufactured process of ink-jet printing. The devices were found to be photoresponsive to broadband incoming radiation in the visible regime. A high ON/OFF ratio ~ 2.3 × 103 and response times on the rising and falling edges, 𝛕rise and 𝛕fall were determined to be ~ 24 ms and ~ 65 ms, respectively. Finally, in this work we also report on the first strain dependent measurements on ink-jet printed perovskite PDs, where the photocurrent Ip decreased by only 27% upon bending with a radius of curvature of ~ 0.262 cm-1. The flexible, ink-jet printed 2D perovskite heterostructure PDs have significant potential for optoelectronic devices which can enable broad possibilities given the compositional tunability and versatility of the 2D organohalide perovskites.
Session: Abstract Session 4
Top-Gate Indium Oxide Transistors by Low-Temperature Atomic Layer Deposition of Gate Insulator and Channel Semiconductor
Mengwei Si, Peide Ye
Purdue University, West Lafayette, IN, USA

In this work, we report the experimental demonstration of top-gate indium oxide (In2O3) transistors by low-temperature atomic layer deposition (ALD) of both gate insulator and channel semiconductor. High-performance top-gate In2O3 transistors are achieved with maximum drain current (ID) of 570 μA/μm and low subthreshold slope (SS) down to 84.6 mV/dec. It is found that the deposition of hafnium oxide (HfO2) as gate insulator at low temperature and post-deposition annealing at low temperature in O2 are critical to annihilate defects that generated during the formation of top dielectrics and top-gate electrode.
Session: Abstract Session 4
Uniaxial and Multiaxial Test Techniques for Reliability Assessment of Flexible and Wearable Electronics
Suresh Sitaraman
Georgia Institute of Technology,

Dramatic advances in materials synthesis and processing, scalable manufacturing, and on-demand and customizable design have led to increasing interest in flexible and wearable electronics for a wide range of application areas such as health care, energy, transportation and mobility, communications, defense and security, safety, water, and food. To sustain and grow the enormous interest in flexible and wearable electronics, it is critical to ensure that flexible and wearable devices and systems are reliable through their intended operational life. In this presentation, I will discuss some of the uniaxial and biaxial reliability test techniques that are under development in our lab, and how these techniques can be employed to mimic in-use conditions of flexible and wearable electronics devices and systems. I will present physics-based computational simulations to provide insight into the stress-strain evolution at various locations, and to demonstrate how damage evolution can be linked to failures. Details from cross-sectional images as well as digital image correlation measurements will also be discussed. I will close the discussion by examining various practical applications and their potential failure modes, and how the developed test techniques can be tailored toward examining such applications. Dr. Suresh K. Sitaraman is a Regents’ Professor and a Morris M. Bryan, Jr. endowed Professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology (Georgia Tech). Dr. Sitaraman is the Lead Faculty for NextFlex at Georgia Tech, and also directs the Computer-Aided Simulation of Packaging Reliability (CASPaR) Lab. His expertise is in the areas of micro- and nano-scale structure fabrication, testing and characterization and physics-based modeling and reliable design, as applied to flexible and rigid microsystems. Prior to joining Georgia Tech in 1995, Dr. Sitaraman was with IBM Corp. Dr. Sitaraman has co-authored more than 320 journal and conference publications over the past few years. He has managed several research and development projects funded by US federal agencies, industry, and other sources totaling millions of dollars, and has mentored a vast array of post-doctoral fellows as well as doctoral, master’s, bachelor’s, and high-school students. Dr. Sitaraman’s work has been recognized through several awards and honors. Among them, he has received the Zeigler Outstanding Educator Award from Georgia Tech/Mechanical Engineering in 2019, the NextFlex Fellow recognition in 2018, the Outstanding Achievement in Research Program Development Award (Team Leader) from Georgia Tech in 2017, the ASME/EPPD (Electronic and Photonic Packaging Division) Applied Mechanics Award in 2012 and the Thomas French Achievement Award from the Department of Mechanical and Aerospace Engineering, The Ohio State University in 2012. Dr. Sitaraman has received the Sustained Research Award from Georgia Tech – Sigma Xi in 2008 and the Outstanding Faculty Leadership Award for the Development of Graduate Research Assistants, Georgia Tech in 2006. His co-authored papers have won the Commendable Paper Award from IEEE Transactions on Advanced Packaging in 2004 and the Best Paper Award from IEEE Transactions on Components and Packaging Technologies in 2001 and 2000. Dr. Sitaraman has also received the Metro-Atlanta Engineer of the Year in Education Award in 1999 and the NSF-CAREER Award in 1997. Dr. Sitaraman serves as an Associate Editor for IEEE Transactions on Components, Packaging, and Manufacturing Technology. Dr. Sitaraman is an ASME Fellow.
Session: Invited Session 4 - Additive Manufacturing
Semiconducting: Insulating Polymer Blends Targeted for Flexible Optoelectronic Applications
Natalie Stingelin
Georgia Institute of Technology,

In recent years, immense efforts in the flexible electronics field have led to unprecedented progress and to devices of ever increasing performance. Despite these advances, new opportunities are sought in order to widen the applications of organic-based technologies and expand their functionalities and features. For this purpose, use of multicomponent systems seems an interesting approach in view of, e.g., increasing the mechanical flexibility and stability of organic electronic products as well as introducing other features such as self-encapsulation. One specific strategy is based on blending polymeric insulators with organic semiconductors; which has led to a desired improvement of the mechanical properties of organic devices, producing in certain scenarios robust and stable architectures. Here we discuss the working principle of semiconductor:insulator blends, examining the different approaches that have recently been reported in literature. We illustrate how organic field-effect transistors (OFET)s and organic solar cells (OPV)s can be fabricated with such systems without detrimental effects on the resulting device characteristics even at high contents of the insulator. Furthermore, we review the various properties that can be enhanced and/or manipulated by blending including air stability, mechanical toughness, H- vs. J-aggregation, etc.
Session: Invited Session 3 - Chemistry & Materials
Group 14 Effects in Alkynyl Acene Small Molecule Semiconductors
Karl J. Thorley1, Micai Benford2, Yang Song2, Sean R. Parkin1, Chad Risko1, John E. Anthony1
1University of Kentucky, Lexington, KY, USA, 2Centre College, Danville, KY, USA

Silylethynyl substitution of organic materials has been commonplace in the last 20 years, due to the solubility and stability that these substituents add to polycyclic aromatic hydrocarbons, and crystal engineering opportunities towards bulk material semiconductivity. While germanium variants have also been synthesised and investigated in transistor devices, carbon equivalents are under-represented. The synthesis of branched all-carbon acetylenes and their attachment to acene materials will be presented, including the substituent influence on single molecule properties and solid state packing relevant to their application in optoelectronic devices.
Session: Abstract Session 1
Low-Noise Flexible Sensor Sheets for Imperceptible Biomonitoring System
Takafumi Uemura
Osaka University,

Takafumi Uemura received B.S., M.S., and Ph.D. degrees in applied physics from Osaka University, Japan, in 2003, 2005, and 2008, respectively. During 2008-2010, he was a Postdoctoral Researcher at Osaka University. During 2010?2013, he was an Assistant Professor of the Institute of Scientific and Industrial Research, Osaka University. During 2013?2015, he was a Project Lecturer at The University of Tokyo. During 2013?2014, he worked at IMEC as a Visiting Professor at KU Leuven, Belgium. Since 2015, he has been a Specially Appointed Associate Professor at Osaka University. His areas of expertise are organic semiconductor physics and flexible electronic devices, and he is promoting the development of applications for digital healthcare and IoT sensor devices.
Session: Invited Session 6 - Systems
Thermal Stability of Flexible IGZO/Ag Schottky Diodes on Cellulose Microfiber Paper Substrate
Sahira Vasquez, Mukhtar Ahmad, Mattia Petrelli, Martina Aurora Costa Angeli, Raheel Riaz, Ali Douaki, Giuseppe Cantarella, Niko Muenzenrieder, Paolo Lugli, Luisa Petti
Free University of Bozen-Bolzano, Bolzano, Italy

In this work, Schottky diodes based on amorphous indium-gallium-zinc-oxide (IGZO) were fabricated on cellulose microfiber paper substrate. Silver lines used as the Schottky barrier were printed, in parallel to thermally evaporated Cr/Au ohmic contact, using a dispense printer. The morphological and electrical characteristics of the devices are presented. The fabricated diodes exhibited rectification ratios ranging from 3.4 to 34.9 at ±1V with ON voltages that range from 1.1V to 1.4 V, for device lengths (Ag to Au distance) from 145 µm to 894 µm. The diodes were characterized in a temperature range between 25oC and 80oC. They showed a decrease of the ON current when increasing temperature, which is mainly attributed to the change of the cellulose microstructure. Indeed, an opposite of the ON current behavior was registered when the diode was realized on a polyimide substrate. The realized flexible paper-based diodes offer a potential promising choice for printed environmental-friendly electronics.
Session: Abstract Session 4
AI Meets The Real World: Sensing Technologies Based on Large-Area Electronics for Advancing Machine Perception
Naveen Verma
Princeton University,

Machine capability has reached an inflection point, achieving human-level performance in tasks traditionally associated with cognition (vision, speech, gameplay). However, efforts to move such capability pervasively into the real world, have in many cases fallen far short, compared to the relatively constrained and isolated demonstrations of success. A major insight emerging is that structure in data can substantially enhance machine learning. This talk explores how complex processes of the real world can be addressed by preforming sensing in ways that preserve the rich structure of the real world. This evokes questions like: what sort of structure is useful; what sort of machine-learning models can exploit such structure; what sensing technologies enable this structure? Large-area/flexible electronics presents unique capabilities for deploying large and expansive arrays of form-fitting sensors, which can enable valuable structure in sensor data. This talk explores technological, architectural, and algorithmic opportunities and advances for harnessing such capabilities in next-generation systems, as well as prototype demonstrations of the resulting systems. Naveen Verma received the B.A.Sc. degree in Electrical and Computer Engineering from the UBC, Vancouver, Canada in 2003, and the M.S. and Ph.D. degrees in Electrical Engineering from MIT in 2005 and 2009 respectively. Since July 2009 he has been at Princeton University, where he is current Director of the Keller Center for Innovation in Engineering Education and Professor of Electrical Engineering. His research focuses on advanced sensing systems, exploring how systems for learning, inference, and action planning can be enhanced by algorithms that exploit new sensing and computing technologies. This includes research on large-area, flexible sensors, energy-efficient statistical-computing architectures and circuits, and machine-learning and statistical-signal-processing algorithms. Prof. Verma has served as a Distinguished Lecturer of the IEEE Solid-State Circuits Society, and on a number of conference program committees and advisory groups. Prof. Verma is the recipient of numerous teaching and research awards, including several best-paper awards, with his students.
Session: Invited Session 6 - Systems
Plasma Jet Printing and Photonic Sintering of Thermoelectric Colloidal Nanoplatelets for Flexible Energy Harvesting
Ariel E. Weltner1, Jacob Manzi2, Tony Varghese2, David Estrda1,3,4, Harish Subbaraman2,3
1Micron School of Material Science and Engineering, Boise State University, Boise, ID, USA, 2Electrical and Computer Engineering Boise State University, Boise, ID, USA, 3Center for Advanced Energy Studies, Boise State University, Boise , ID, USA, 4Idaho National Laboratory, Idaho Falls, ID, USA

Flexible thermoelectric generators (f-TEG) are a promising power source for self-powered and/or wearable electronic devices. Despite advances in thermoelectric material properties, direct conversion and integration of nanomaterials into a functional device remains a challenge. Here we demonstrate large-scale synthesis of nanomaterials and development of a flexible printed thermoelectric generator using atmospheric pressure plasma jet printer (PJP) and intense pulse light (IPL) sintering techniques for the first time. Room temperature printing and high adhesion offered by plasma jet printing promotes development of f-TEG on to a wide variety of flexible substrates. This highly scalable and low-cost fabrication of f-TEG creates new opportunities for the integration of thermoelectric power sources into flexible hybrid electronic devices.
Session: Abstract Session 5
Flexible Multilayer Printed Circuit Board Prototype Offering for Confined Form Factors
John Williams
Boeing Research and Technology,

Boeing is rapidly prototyping multilayer flexible printed circuit boards (Flex-PCBs) for size weight power and cost saving applications. Flex PCBs allow electronics to be wrapped onto cylindrical or bi-axial curved surfaces. Conventional Flex PCBs contain either one to four copper layers with limited electronic packaging. Most devices are bonded on either end to rigid boards that contain complex packaged electronics. However, our process extends this effort to complete the entire electronics application from single to eight layer boards. Thus allowing antennas, sensors, communication links, and radars to be placed directly onto the surface of a vehicle. Similarly, power routing, and microcontrollers can conform to the surface or interior cavity. This technology provides a transformative approach to packaging PCBs in aerospace applications. Our team has demonstrated this capability on RF boards with no less than 500 through vias, 100 buried vias, and 50 electronically packaged components. Boards can be turned in days without electroplating. Pyralux AP polyimide substrates from DuPont, Taconic, and 3M bonding adhesive achieves alignment errors of 2 mil or less over an 8 x 10 square inch area. Kapton substrates can also be used with additional alignment risk. Patterning can be completed with either copper or silver ink. Vias are filled using conductive inks. Electronic packaging is currently performed using anisotropic conductive epoxy, but industrially standard solder attach is also available for copper clad and plated devices. Cost models have been completed for printed silver devices, documenting the manufacturability from MRL 4 to 6. We are currently examining pilot capability of different suppliers to manufacture devices as needed. Dr. Williams is an Associate Technical Fellow and the lead engineer for Additive Electronics Manufacturing at Boeing Research and Technology (BR&T) in Huntsville. After completing his PhD, John served as the science and technology lead for the Metal Micromachining effort at Sandia National Laboratories in Albuquerque, NM. He later joined the University of Alabama in Huntsville as an Assistant Professor of Electrical, Materials, and Optical Engineering and Associate Director of the their Nano and Micro Devices Center. Dr. Williams has more than 15 years of experience as a PI lead for prototype development of microelectromechanical systems (MEMS) with over 27 patents and 40 peer reviewed publications in the areas of materials processing, metals, microfabrication, photonics, and RF electronics and bioMEMS. Dr Williams’ research has been funded by NSF, DARPA, NASA, NIH, and US ARMY-SMDC. He is currently the Principal Investigator on five NextFlex projects used to improve manufacturing readiness of materials and processes to multilayer layer printing of DC electronics, antennas, and complex multilyaer printed circuit boards for RF applications.
Session: Invited Session 4 - Additive Manufacturing
A Novel MWCNTs/PDMS based Flexible Triboelectric Nanogenerator for Energy Harvesting Applications
Xingzhe Zhang, Duo He, Dinesh Maddipatla, Qiang Yang, Massood Atashbar
Western Michigan University, Kalamazoo, MI, USA

A novel multi-wall carbon nanotube /polydimethylsiloxane (MWCNTs/PDMS) and polyvinylidene fluoride (PVDF) based flexible triboelectric nanogenerator (TENG) was fabricated for energy harvesting applications. The TNEG was fabricated by using the MWCNTs/PDMS layer (anode), aluminium (Al) electrode and PVDF layer (cathode). The MWCNTs/PDMS layer was fabricated using bar-coating process. A surface roughness and thickness of ~0.34 µm and 1 mm was measured for the fabricated MWCNT/PDMS, respectively. The capability of the TENG in terms of open circuit voltage (OCV) and short circuit current (SCC) was investigated by subjecting it to a force of 5 N, 10 N and 15 N at varying frequencies of 3 Hz, 5Hz and 7 Hz respectively. The maximum OCV of 21.6 V and SCC of 1.7 μA was obtained for an applied force of 15 N at a frequency 7 Hz, respectively.
Session: Abstract Session 5