• Printed and Flexible Electronics and Devices: An Overview

    The rapid emergence of the Internet of Things era has led to increased research activities in the area of printed and flexible electronics. The research areas include, but not limited to, ink development and characterization, printing tool and process development to obtain desirable characteristics of printed conductors, semiconductors and dielectrics, post-processing including annealing, and demonstration of various printing applications on a wide variety of flexible substrates including paper, plastics and textiles. This tutorial will provide an overview of the above topics and applications for printing including gas sensors, biosensors, UV and other radiation detectors, supercapacitors, triboelectric nanogenerators (TENGs), memory devices, electromagnetic interference (EMI) shielding, metasurfaces and others. The author thanks Jin-Woo Han, Myeonglok Seol, Beomseok Kim, Sunjin Kim, Dongil Moon, Dongil Lee, Kyung Jean Yoon, Jessica Kohene, Ram Gandhiraman, Daniel Gutierrez and Pranay Doshi for their contributions.

  • Nanocarbon-Based Flexible and Stretchable Electronics

    Flexible and stretchable electronics has drawn intense interests because of their potential for emerging applications, providing imperceptible wearable devices and skin prosthesis repair for humans, soft perceptions for intelligent robots, and conformable interfaces for human-machine interactions, especially in the era of Internet of Things and fifth generation wireless technologies. At the same time, flexible electronics encounters challenging obstacles of material self-limiting fabrication, trade-off mechanical flexibility, and associated moderate electrical performance. Nanocarbon based electronics is of great promise to solve these problems for their intrinsic flexibility or stretchability, high carrier mobility, potential for large-area integration and capability to synthesize as semiconducting or metallic. An ideal carbon-based soft electronic system covering transistors and circuits for logic processing and control, sensors for acquiring information, energy generators or harvesters for self-power, displays for intuitive presentation, and neuromorphic electronics for intelligence, would provide novel solutions and open versatile doors for human life experience. This tutorial will provide an overview of the devices or circuits above, as well as the integration methods, materials and mechanisms.