Piezoresistive Pressure Sensors with Composite Film of Indium Tin Oxide Nanocrystals Dispersed in Poly(vinyl alcohol)

Abstract

Flexible pressure sensors have attracted much attention because of their application prospects in wearable devices, electronic skin, and health monitoring. However, it is still difficult to obtain pressure sensors with excellent performance simply and efficiently. Indium tin oxide (ITO) is a widely used transparent conductive material, and polyvinyl alcohol (PVA) is an elastic insulating material with the advantages of easy processing and stable mechanical properties. ITO nano‐crystalline particles are dispersed into PVA polymers to form an ITO nanocrystalline‐PVA composite film with good electrical conductivity as a piezorestoresistive material, fabricating a pressure sensor with excellent performance. The pressure sensor possesses superior sensitivity (641.15 kPa−1), wide detection range (0–80 kPa), fast response time (10.93 ms), and recovery time (8.05 ms), and excellent stability (more than 1500 cycles). The pressure sensor shows excellent performance in a variety of applications, such as pulse testing, speech recognition, and detection of various joint movements of the human body (such as knees, fingers, elbows, etc.). The sensor has application prospects in health monitoring and motion perception.