Direct Laser Patterning of Free-Standing RGO Electrodes for Wearable Capacitive Pressure Sensors

Abstract

Graphene-based flexible pressure sensors are promising for cutting-edge applications, for instance, e-skins, human-machine interaction, and wearable health-monitoring devices. However, the development of free-standing graphene electrodes with well-designed patterns is still challenging. Herein, we report the direct laser patterning of a pair of free-standing reduced graphene oxide (RGO) electrodes with complementary helical microstructures for developing high-performance capacitive pressure sensors (CPSs). A commercially available porous tape was sandwiched between the two RGO electrodes. The design and fabrication of the complementary helix-shaped RGO electrodes are essential for developing CPSs with improved sensing performance. The resultant CPSs enable dual-mode sensing detection (pressure and proximity) with a high sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 0.95$ </tex-math></inline-formula> kPa−1. As a proof-of-concept application, the RGO-based CPS has been employed as wearable electronics for finger motion monitoring.