Effects of temperature on MWCNTs/PDMS composites based flexible strain sensors

Conductive polymer composites (CPCs) are widely used in the flexible strain sensors due to their simple fabrication process and controllable sensing properties. However, temperature has a significance impact on the strain sensing performance of CPCs. In this paper, the strain sensing characteristics of MWCNTs/PDMS composites under temperature loading were systematically studied. It was found that the sensitivity decreased with the increase of temperature and the phenomenon of shoulder peak also decreased. Based on the theory of polymer mechanics, it was found that temperature could affect the conductive network by changing the motion degree of PDMS molecular chain, resulting in the change of sensing characteristics. Finally, a mathematical model of the resistance against loading condition (strain and temperature), associated with the force-electrical equivalent relationship of composites, was established to discuss the experimental results as well as the sensing mechanism. The results presented in this paper was believed helpful for the further application of strain sensors in different temperature conditions.