Ultra‐Flexible Biodegradable Pressure Sensitive Field Effect Transistors for Hands‐Free Control of Robot Movements

Abstract

Sensitive flexible pressure sensors are needed in applications such as health monitoring, robotics, and wearable systems. Herein, crumpled graphene flakes network (c‐GFN) channel based highly sensitive pressure sensing field effect transistors (PRESSFETs) are presented. The solution‐processed PRESSFET devices are developed on ultrathin (≈3 μm thick) biodegradable graphene oxide–chitosan (GO–CS) substrate. The distinctive crumpled morphology of GFN leads to a bandgap of 800 meV, which allows the device to have clear ON and OFF electronic states and low subthreshold swing. The presented device can work over a dynamic pressure range (0.5–2 kPa), while exhibiting good electrical stability and repeatability during rapid switching. The application of the presented device is demonstrated by attaching them to the temple regions of the face and pressing them with flexure and relaxation of respective temporalis muscles for hands‐free control of the movements of a robotic device. The pressure sensing device turns ON when the facial temporalis muscle is flexed and returns to the OFF state when it is relaxed. Finally, the degradability of the devices is presented to demonstrate their easy disposability and potential for zero electronic waste.