Wearable Piezoresistive Pressure Sensor Based on Graphene and PDMS Nanocomposite Sponge for Foot Steps Detection

Abstract

Wearable sensors based on nanocomposite sponge are gaining popularity due to their high sensitivity, stretchability and offer new opportunities for applications ranging from finger motion detection to soft robotics. However, when designing skin-adaptable, mountable, or non-invasive wearable devices, several features need to be taken into account, such as stretchability, flexibility, sensitivity, and biocompatibility. Herein, we present a facile, cost-effective, flexible, and stretchable piezoresistive pressure sensor based on a graphene/polydimethylsiloxane (PDMS) nanocomposite sponge (GPNCS) for finger motion detection. The maximum sensitivities were 133.95 kPa ⁻¹ for the pressure range of 1–10 N and 5.05 kPa ⁻¹ for the pressure range of 10–20 N respectively. When various pressures are applied, the pressure response of the devices are highly stable, repeatable, and reversible. Moreover, the piezoresistive pressure sensor has excellent sensing performance at various pressures ranging from 1 to 20 N and is mechanically robust enough to work under repeated load without degradation. The proposed device demonstrated an exceptional ability to monitor small and large finger motion, which has numerous applications in the range of finger motion detection, flexible insole as wearable healthcare monitoring and gait monitoring device