Flexible piezoresistive strain sensor with high sensitivity based on carbonised waste thermosetting resin

Abstract

In this study, a novel flexible piezoresistive strain sensor was prepared by using polydimethylsiloxane (PDMS) to encapsulate carbonised waste polybenzoxazine (cPBa). Benefiting from the porous conductive framework of cPBa, the infused PDMS endowed the cPBa/PDMS strain sensor with excellent mechanical properties. It was observed that this sensor exhibited both negative and positive piezoresistive effects due to the conductive disconnection/reconnection process of carbon fragments while monitoring compressive deformation. Moreover, it showed a high sensitivity with a gauge factor (GF) of 1954.3 at the strain range of 12–30% and excellent repeatability (up to 1000 cycles). Also, the potential application of this strain sensor in monitoring human body motions was evaluated. This work presents an eco-friendly way to fabricate highly sensitive flexible strain sensors using recycled thermosetting resins.