Fabrication and transfer of laser induced graphene (LIG) electrode for flexible substrate-based electrochemical sensor applicatins

Abstract

This paper describes the fabrication process of laser induced graphene (LIG) and its transfer method on to a flexible and stretchable PDMS substrate. By irradiating CO2 laser on a polyimide(PI) film surface, a localized high temperature is created, resulting in a three-dimensional porous graphene network structure with good conductivity. This LIG electrode is relatively easy to fabricate and since it is very weak the LIG electrode was transferred to a flexible PDMS substrate to increase the sturdiness as well as possible use in flexible applications. Sheet resistance, thickness, and electrochemical activity of the fabricated in-situ LIG electrodes have been examined and compared with the LIG electrodes after transferring to PDMS elastomer. The properties of the LIG electrodes were also examined depending on the CO2 laser power. As the irradiated laser power increased, the LIG electrode resistance decreases and the LIG electrode thickness increased. At 4.8 W of laser power, the average sheet resistance and thickness of the fabricated LIG electrodes were approximately 31.7 Ω/ □ and 62.67 μm, respectively. Moreover, the electrochemical activity of the fabricated LIG electrode at 4.8 W of laser power showed a high oxidation current of 28.2 μA after transferring to PDMS. © Copyright The Korean Institute of Electrical Engineers.