A Flexible Resistive Pressure Sensor Based on Thermally Expandable Microspheres

flexible pressure sensors, as important parts of electronic skins, have attracted great attention for their great potential applications in soft robot, wearable electronic device and biomedical diagnosis. Pressure sensors based on resistive working mechanisms have attracted more attention owing to their high reliability, facile fabrication techniques and low energy consumption. Recently, great efforts have been focused on increasing the sensitivity of flexible pressure sensors, however, developing high-sensitive pressure sensors with a cost-effective fabrication method are still challenging. In this study, a new type of flexible pressure sensor with great sensitivity of 4.11 kPa-1, fast response time (<35 ms) and high stability (1000 cycles of pressure loading/unloading) has been designed based on thermal expandable microspheres. In addition, the fabricated pressure sensor is successfully applied to detect tiny human motions (deglutition, vocal cord vibration) and monitor finger bending. More importantly, because of the simple fabrication, the flexible pressure sensor can easily achieve large-scale production.