A Highly Sensitive Flexible Pressure Sensor Based on Inter-Comb Structured Graphene Electrodes

Abstract

Susceptible and flexible pressure sensors have broad application prospects and market demands in bionic skin, human–machine interface, and intelligent wearable electronic devices. However, optimizing the sensor’s sensitivity through a simple, low-cost process is still a considerable challenge. In this work, the sensitivity of a capacitive pressure sensor was effectively improved by optimizing the geometry of the laser-scribed graphene (LSG) electrodes. The pressure sensor, based on the inter-comb structured LSG electrodes and polyvinyl pyrrolidone nanofiber membrane (PVP NM) dielectric layer, has a high sensitivity (4.352 kPa <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-\text{1}}$</tex-math> </inline-formula> at 0–2 kPa), a fast response/recovery time (40/37 ms), an ultralow detection limit ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 12 Pa), and excellent mechanical stability (6000 cycles). The sensor developed in this research can be used in health monitoring such as carotid artery pulsation and respiratory disease. In addition, the 6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> 6 sensor array can precisely characterize the regional pressure distribution. This study demonstrates the significant potential of the inter-comb structured LSG electrodes in highly sensitive flexible pressure sensors.