Highly stretchable and sensitive conductive rubber composites with tunable piezoresistivity for motion detection and flexible electrodes

Highly stretchable conductive polymer composites and highly sensitive flexible strain sensors have broad application prospects for wearable electronic devices such as human motion monitoring. In this paper, excellent stretchable and high conductive rubber composites based on room temperature vulcanized (RTV) silicone rubber with carbon fiber (CF) and carbon black (CB) are prepared through the solution method and the ultrasonic dispersion technology. The morphology results show that CF and CB in the composites formed a 3D collaborative conductive network of bridge connection. Then, both the sensitive characteristic and strain-sensing mechanism of CF/CB-RTV silicone rubber sensors have been investigated, which exhibits excellent stretchability as high as 700% and has a good linear relationship with 0–375% strain range and the maximum gauge factor of 182. Also, it has been found that the composites with 12.5 wt% CB maintained good electrical conductivity in the case of large deformation. Finally, CF/CB-RTV conductive composites have been used for human motion monitoring with high sensitivity, and as flexible electrodes in LED bulbs, which still have significant brightness under the 300% strain of the composites with 12.5 wt% CB.