With the rise of intelligent wearable electronics and internet of things (IoT), flexible sensors and energy harvesters that can convert rich but irregular mechanical energy/signal into electrical energy/signal have attracted much attention, as this method can reduce the dependence on batteries. Herein, various flexible sensors and generators based on electret and piezoelectret materials are successfully fabricated, with the fundamental working mechanism of electrostatic induction caused by the surplus charges. Specifically, the charges capturing ability of the electret and piezoelectret materials and the structure of the devices are optimized, in order to improve the output power of the generators and the sensitivity of the sensors. These flexible sensors and generators have been demonstrated the applications in mobile health care, human interaction and wireless communication, etc. These works not only offer new valuable insights, but will open up new perspectives to develop self-powered systems with high properties.
Dr. Junwen Zhong is a postdoctoral researcher in University of California, Berkeley, and is working with Prof. Liwei Lin at Berkeley Sensor & Actuator Center (BSAC). He received his B.S. degree (2011) and PhD degree (2016) from Huazhong University of Science and Technology, China. He majors in flexible generators, self-powered systems, active sensors, and mechanical actuators. He has published 7 patents, 1 book chapter and over 22 papers, among which 10 papers were published as the first author. Some of his papers were published in Energy & Environmental Science, Advanced Materials, ACS Nano, and Nano Energy, with over 1270 citations. Some of his researching works have been reported by Nature Nanotechnology, Scientific American, Chemical & Engineering, News, Nano Werk as highlights.
Smart phones, cars, and wearable activity trackers are just a few examples of products with sensors based on technologies pioneered at the Berkeley Sensor & Actuator Center, a Graduated NSF Industry/University Cooperative Research Center for Micro/Nanoelectromechanical Sensors & Systems (MEMS/NEMS). New research at BSAC will have even greater impacts on consumer, industrial, and medical products.