Wide Temperature Range Responsive Flexible Sensors Based on Whisker Carbon Nanotube/Fluorosilicone Elastomer Composite Films

Abstract

Flexible sensor devices have been the subject of considerable research interest due to their potential for a wide range of applications in the fields of wearable devices and human–computer interaction. However, significant challenges still have to be confronted in order to obtain a combination of good chemical stability, a wide temperature domain response, and a stable sensing performance. In this work, fluorosilicone elastomer (FSE)-based composite films were prepared using structurally controllable fluorosilicone prepolymers (FSP) as prepolymers and whisker carbon nanotubes (WCNTs) as a well-dispersed conductive filler. The mechanical and sensing properties of the WCNT/FSE composite films were regulated by adjusting the monomer ratio, cross-linking process, and WCNT solid content. The tensile strength and elongation at the break of the composite films are 0.705 MPa and 306%, respectively, when the solid content of WCNTs was 5 wt %. The relative resistance change of the film was observed to be as low as −0.09% at relative humidity levels ranging from 45 to 85%. Over the temperature range of −30 to 150 °C, the film exhibited a negative temperature coefficient of resistance (TCR), stabilizing around −0.0026%/°C. The cyclic tensile properties of WCNT/FSE demonstrated resistance to temperature over the temperature range of −20 to 100 °C and exhibited a robust response to tensile deformations from 5 to 30%.