Joseph Chang - A highly-efficacious Self-compensation Means to Reduce Variations

Session 4: FPE Technologies

A highly-efficacious Self-compensation Means to Reduce Variations due to the Bending of the Substrate
Tuesday, June 20, 2017 
3:00 PM - 3:20 PM

Joseph S Chang, Tong Ge and Jia Zhou

One of the key challenges of Printed Electronics (PE) is that the variations of the characteristics of PE elements and circuits when its substrate is bent. In many cases, as the degree of bending is unknown, e.g., when the substrate is adhered to the knee, these variations are intractable. At this juncture, the two solutions are to either use a very-thin substrate or to deposit another substrate layer of equal thickness over the top of the original substrate. These means are often impractical and limiting. We propose a novel highly-efficacious self-compensation means involving printing one half of a given printed element on the top surface of the substrate and the other half on the bottom surface. This exploits the fact that when a substrate is bent, the top surface and bottom surface experience opposing stresses. We demonstrate the efficacy of our proposed methodology by means of measurements on PE elements and complete circuits. For example, when the substrate is bent with radius of 2cm, the variations of the Thin-Film-Transistor, capacitor and resistor respectively reduce by a very significant 26x, 5x and 15x; x = times. In the case of printed circuits, the variations of the threshold/switching voltage of the diode-connected inverter, oscillating frequency of the zero-VGS connected ring oscillator, and unity gain-bandwidth of an operational-amplifier respectively reduces by a very significant 13x, 108x and 6x. Our proposed means does not incur hardware, area or power overheads although a means to print both sides of the substrate is necessary.


Speaker's Biography

Joseph received his PhD from the Department of Otolaryngology, The University of Melbourne. He is a professor and the director of Virtus-IC Design Center of Excellence at the Nanyang Technological University, Singapore, and an adjunct professor at the Texas A&M University (USA). His research is multi-disciplinary, including ECE (analog, mixed-signal and digital electronics; and aerospace electronics), bioengineering (audiology/acoustics and microfludics), and printed electronics. He has received several Best Papers awards and numerous research grants, including from DARPA (USA), NSF (USA), the EU, industry and local funding agencies. He has founded two start-ups. He has 30 awarded and pending patents, and has commercialized a number of his innovations. He has/is served/serving as the corresponding Guest Editor-In-Chief of the IEEE Journal of Emerging Topics and Selected Topics (Organic Electronics: A Circuits and Systems Perspective), the Proceedings of the IEEE and the IEEE Circuits and Systems Magazine, and as senior editor, editor and associate editor of numerous IEEE journals. He has also served as General Chair of several major IEEE-NIH conferences/workshops, as the keynote speaker of several major conferences, and Chair of several IEEE Technical Committees.


Joseph Chang
Nanyang Technological University Singapore