A Highly Sensitive Flexible Capacitive Pressure Sensor with Micro-array Dielectric Layer

The application of flexible pressure sensors is gradually extended to electronic skins, wearable sensing devices, and humanoid robotics, which are the key to realize artificial intelligence that can contact with humans directly, and to the biomedical applications such as smart prosthesis. In the aforementioned advanced applications, high sensing capability, fast response, high working stability are essential features for the flexible pressure sensors. Although the surface microstructure treatments for electrodes of pressure sensors have been applied to improve sensitivity, the complex process raises the cost and become an obstacle to large-scale manufacturing. In this study, a highly sensitive, low-cost, transparent and flexible capacitive pressure sensor with micro-array polydimethylsiloxane (PDMS) dielectric layer has been developed using a facile fabrication strategy. The pressure sensor was fabricated by integrating substrates, micro-array PDMS dielectric layer and silver nanowires (AgNWs) electrode layers. The as-fabricated flexible pressure sensor shows high sensitivity (>2.1 kPa(-1)), fast response (<100 ms) and high cycle stability (>5000 times). The facile fabrication process can be easily scaled up to form pressure sensor arrays, which can be applied to wearable sensing devices or electronic skins.