Generation of Microscale Triboelectric Signals for Development of Self-triggered Sensors
Dongwhi Choi
Department of Mechanical Engineering (Integrated Engineering), Kyung Hee University, Yongin, South Korea
dongwhi.choi@khu.ac.kr
Abstract
Triboelectricity, which is generated from sequential contact and separation of two different materials including liquid, is highlighted as a novel mechanism for development of various types of self-powered sensors. In this study, two types of self-triggered sensors, where the operation mechanism is based on the triboelectricity, are proposed. Considering that the surface to volume ratio becomes large in microscale systems and thus, the phenomenon at the interface becomes dominant, the triboelectricity can generate considerable amount of the electric signals in microfluidics. In this regard, the self-triggered gas slug sensor, which enables us to inform various characteristics of the gas slug in microfluidic channels, is proposed. Since the electric signal can be generated without any other external power sources, the present sensor can be considered as self-triggered. Furthermore, the solid-solid contact/separation is utilized to develop the smart gear. Gear is one of the most ordinary and effective components for transmitting mechanical power as a core component of machines. Given that the operation of the gear in power transmission is based on sequential contact and separation between two engaged gear teeth, the simple modification of the outermost surface of the conventional gear enables us to spontaneously generate triboelectric signal during ordinary power transmission. The present approach to utilize microscale triboelectric signals could open new application fields with various types of self-triggered sensors.
Short Bio
Prof. Dongwhi Choi received his Ph. D. in department of mechanical engineering from the Pohang University of Science and Technology (POSTECH), Korea in 2016 and continued with his postdoctoral research at the POSTECH during the years of 2016-2018. Subsequently, Prof. Choi joined the department of mechanical engineering, Kyung Hee University, Korea as an assistant professor in 2018. His main research interest is based on development of various novel types of polymer based platforms/devices considering mechanical properties of materials to advantageously utilize spontaneously generated electric signals from various mechanisms including triboelectricity and piezoelectricity. As core application fields, the energy harvesters and self-triggered sensors are intensively studied in his group.