An Omni-Healable and Highly Sensitive Capacitive Pressure Sensor with Microarray Structure

Capacitive pressure sensors with high flexibility, sensitivity, and excellent healable properties are desirable for a wide variety of applications, such as e-skin. However, implementing these characteristics onto a device presently remains a great challenge. In this work, a flexible pressure sensor with high sensitivity and strong healable properties has been developed based on healable polyurethane (HPU), silver nanowires and graphene. The HPU-based microstructured capacitive pressure sensor exhibited a high sensitivity of 1.9 kPa(-1) (<3 kPa), a fast response time (<100 ms), low detection limit (10 Pa), and long-term durability (1000 cycles). Touch-finger and vocal-cord vibration detection have been demonstrated and exhibit a high sensitivity to both static and dynamic pressure. More notably, the entire pressure sensor including the dielectric layer and electrodes is omni-healable after complete separation. The prototype has experimentally shown tremendous potential for wearable, healable applications, such as healthcare monitoring and human-machine interfaces.