Highly Sensitive Piezocapacitive Sensor for Detecting Static and Dynamic Pressure Using Ion-Gel Thin Films and Conductive Elastomeric Composites

A new class of simple and highly sensitive piezocapacitive sensors that are capable of detecting static and dynamic pressure changes is reported. The pressure sensor structure is formed by vertically sandwiching a sandpaper-molded carbon nanotube/poly­(dimethylsiloxane) composite (CPC) dielectric layer between two ion-gel thin film electrodes. Such a capacitive sensor system enables the distinguishable detection of directional movement of applied pressure as well as static pressure variation by modulating ion distribution in the ion-gel thin films. The resulting capacitive pressure sensors exhibit high sensitivity (9.55 kPa^–1), high durability, and low operating voltage (0.1 V). Our proposed pressure sensors are successfully applied as potential platforms for monitoring human physiological signals and finger sliding motions in order to demonstrate their capability for practical usage. The outstanding sensor performance of the pressure sensors can permit applications in wearable electronic devices for human–machine connecting platforms, health care monitoring systems, and artificial skin.