High-Linearity\nFlexible Pressure Sensor Based on the\nGaussian-Curve-Shaped Microstructure for Human Physiological Signal\nMonitoring

Abstract

Flexible pressure sensors with high-performance show\nbroad application\nprospects in health monitoring, wearable electronic devices, intelligent\nrobot sensing, and other fields. Although flexible pressure sensors\nhave made significant progress in sensitivity and detection range,\nmost of them still exhibit strong nonlinearity, which leads to significant\ntroubles in signal acquisition and thus limits their popularity in\npractical applications. It remains a serious challenge for the flexible\npressure sensor to achieve high linearity while maintaining high sensitivity.\nHerein, a doped sensing membrane with a uniformly distributed Gaussian-curve-shaped\nmicropattern array was developed using the micro-electromechanical\nsystems (MEMS) process, and a flexible sensor structure with the doped\nfilm as the core was designed and constructed. The prototype sensor\nhas a high sensitivity of 1.77 kPa^–1 and a linearity\nof 0.99 in the full detection range of 20 Pa to 30 kPa. In addition,\nits excellent performance also includes fast response/recovery times\n(∼25/50 ms) and long-term endurance (>10,000 cycles at 15\nkPa).\nThe prototype sensor has been successfully demonstrated in human pulse\nmonitoring, speech recognition, and gesture recognition. The 2 ×\n6 sensor array can detect the spatial pressure distribution. Thus,\nsuch a microstructure shape design will open a new way to fabricate\na high-linearity pressure sensor for potential applications in health\nmonitoring, human–machine interaction, etc.