Fabrication of a strain sensor from a thermoplastic vulcanizate with an embedded interconnected conducting filler network

Conductive polymer composites for use as stretchable strain sensors have recently been developed for use in wearable electronic devices capable of detecting various stimuli such as human body motion. In this work, we report the development of a flexible strain sensor based on conductive thermoplastic vulcanizate (TPV) by the incorporation of conductive carbon black (CCB). By adopting special processing conditions, the percolation threshold of the CCB could be minimized to a value as low as ~4 wt% as compared to a value of 10 wt% for conventional TPV. Under static and cyclic loading, the strain sensing behavior of the conductive TPV depended on the morphology and filler content. The result also revealed that interconnected TPV exhibited superior piezoresistive characteristics with good sensitivity. Therefore, the good strain sensing performance of this conductive TPV can be considered as a promising material for use in wearable human-motion and wearable strain sensors.