Flexible Electronics
| Research @ Osaka University | 2016 |
Flexible, organic electronics will enable and advance an Internet of Things future by allowing flexible, soft sensors to be omnipresent everywhere. The goal of this project was to create a flexible organic device that can read brain waves and control a robot. Demonstration of this would display the potential of an IoT future with flexible sensors.
To accomplish the demonstration, flexible organic circuits were fabricated in the clean room and integrated with a wireless electroencephalogram (EEG) device. The difficulty is in the amplification of brain waves micro-volt to milli-volt and in the integration itself which has never been done.
Our fabricated circuit is a PSEUDO CMOS circuit which showed strong amplification and attained a voltage gain max of 1400. Our characteristic graphs had low hysteresis, high gain, and a sharp inverter curve; characteristics ideal for a transistor.
The device was tested by sending a signal using a frequency generator and observed as an amplified signal on our bluetooth module, demonstrating integration was possible.
This project paves the path toward a new generation of IoT sensors. Amplifying signals as small as microvolt to millivolt allows us to detect most electrical signals that occur in our world. A few applications include immediate care for Alzheimer’s & heart irregularities as well as optimization of sleep for athletes. The latter is of special interest to Japan as countries are gearing their athletes for the Tokyo 2020 Summer Olympics.
Future work involves a fully integrated device: one flexible sheet consisting of feedback resistor, input capacitor, amplifier circuit, and soft silver electrode. The presentation poster for this project can be downloaded here.
This project was conducted under the close mentorship of Dr. Takafumi Uemura in Dr. Tsuyoshi Sekitani’s Advanced Electronic Devices Lab at the Institute of Scientific and Industrial Research at Osaka University. Funding was made possible through the Nakatani RIES Fellowship implemented by Rice University.
References:
Bao, Z., Locklin, J., 2007. Organic Field Effect Transistors. CRC Press. Brütting, W., Adachi, C., 2012. Physics of Organic Semiconductors. WileyVCH. Klauk, H., Chemical Society Reviews 39.7 (2010): 2643-2666. Klauk, H., 2012. Organic Electronics II. WileyVCH. Sekitani, T., and Someya, T., Materials Today 14.9 (2011): 398-407.