Transfer of laser induced graphene onto the surface of cotton fabric: An efficient electrode for triboelectric nanogenerator

Abstract

An electrode in triboelectric nanogenerator (TENG) plays a pivotal role in developing efficient and ultrasensitive devices. However, it has received relatively little attention from researchers, whereas numerous studies on TENG to date have primarily focused on device engineering, material selection, and efficiency improvements. Laser-induced graphene (LIG) demonstrates superior ability to collect charges generated through triboelectrification in TENGs. This article presents a successful fabrication of highly crystalline, conducting and sp²-hybridised LIG on a polyimide (PI) surface, which was subsequently transferred from the PI surface onto the cotton fabric substrate by controlling temperature and pressure. This facilitates the development of a TENG that delivers significantly higher electrical output compared to one using a conventional aluminium electrode. We report a comparative study of two TENGs: in both cases, cotton fabric and ecoflex were used as the tribo-positive and tribo-negative materials respectively. However, in one case the LIG electrode fabricated on cotton fabric was used and referred to as CLIG-TENG, while the conventional aluminium electrode was used in another TENG, referred to as C-TENG. The CLIG-TENG demonstrated 160%, 150%, and 190% higher voltage, current, and power output respectively, compared to the C-TENG. The enhanced performance of the CLIG-TENG is attributed to the strong bindings between LIG and cotton fabric, work function, and dielectric of the LIG attached cotton fabric. Furthermore, the CLIG-TENG exhibited excellent stability over 10,000 cycles demonstrating the durability of the transferred LIG. The ultrasensitive properties of the CLIG-TENG have also been validated through various healthcare sensing applications.