A triangular wavy substrate-integrated wearable and flexible piezoelectric sensor for a linear pressure measurement and application in human health monitoring

Abstract

In this article, we present a triangular-wavy-substrate pressure sensor (TWSPS) consisting a microstructural substrate, a polyvinylidene fluoride (PVDF) film, an elastic layer, and a flexible measuring circuit for real-time monitoring of external pressure variation. A force-electric coupling model is computed to clarify the physical mechanism of strain and response charge amplification with four types of substrate structures in the proposed sensor system. The simulation results show that the response charge initially increases, and then decreases when the contact angle (α) increases. The maximum value of the response charge is about 1.21e−10C at α of 54°. Moreover, the experimental results show that the TWSPS can measure low pressures within 500 Pa with linear response and high sensitivity (19 mV/kPa). More importantly, the design strategy of substrate stain amplification introduced in this work can be fitted with any piezoelectric or piezoresistive material to form a high-performance pressure sensor.