A thin all-elastomeric capacitive pressure sensor array based on micro-contact printed elastic conductors

Abstract

We present a highly elastic capacitive pressure sensor array based on a thin all-elastomeric platform suitable for being integrated onto surfaces with a complex curvature like human skin. The proposed skin-like sensors are simply fabricated by a combination of soft-lithographic replication and contact printing based micro-patterning of a conductive elastomeric ink (carbon nanotube (CNT)-doped polydimethylsiloxane (PDMS)) in a precise and cost-effective manner. The electrical responses of the devices are highly linear, reliable, and reversible when subjected to pressure and tensile strain. Moreover, the devices are mechanically robust enough to be operated stably under various elastic deformations without any structural failure or degradation in performance. In addition, we show that the sensors have possibilities for being employed practically as artificial skins by demonstrating devices that can detect different types of human motions (finger bending and gripping) and spatial pressure distributions generated by the stamps with different protrusion patterns.