Printed Low-Hysteresis Stretchable Strain Sensor Based on a Self-Segregating Conductive Composite

Abstract

The hysteresis of stretchable composites raises significant challenges in the accuracy, reliability, and stability of stretchable strain sensors. Herein, we report a self-segregating conductive composite that overcomes these issues in printed stretchable strain sensors. This printable composite possesses self-segregation between polydimethylsiloxane and carbon black, which was induced by a deep eutectic solvent. Compared with that of the conventional composites with a random conductive network, our spontaneously formed conductive architecture exhibits superior electromechanical performance: (i) low hysteresis and high sensitivity, (ii) high conductivity and low elastic modulus, and (iii) excellent reliability and stability. Moreover, the composite can be applied directly to a simple stencil printing process without any complex ink synthesis and post-treatment of the fabricated device. This work provides a materials design strategy for achieving low mechanical and electrical hysteresis in a conductive composite. The fabricated sensors exhibit comprehensive performance capabilities appropriate for whole body human motion detection as a proof of concept.