Modulating the sensing behaviors of poly(styrene-ethylene-butylene-styrene)/carbon nanotubes with low-dimensional fillers for large deformation sensors.

Abstract Thermoplastic elastomer (TPE) incorporates the large deformation capability of rubber with the formability and recyclability of thermoplastics. When mixed with conductive carbon allotropes, it has potential application for sensors. Herein, various weight ratios of one-dimensional carbon nanotubes (CNTs) to zero-dimensional carbon black (CB) are introduced to the biocompatible TPE poly(styrene-ethylene-butylene-styrene) (SEBS) system to modulate its sensing behaviors, including electrical, mechanical hysteresis and piezoresistive sensitivity properties. The lowest percolation threshold is achieved experimentally when this ratio is 1:3. Energy loss due to the mechanical hysteresis decreases when CNTs are replaced with CB, which indicates a good recoverability for sensors under repeated stretching and releasing loads. Respecting to piezoresistive sensibility, theoretical models are proposed to explain the sensing mechanism. Especially, the highest gauge factor (GF = 9.872) meaning the highest sensitivity is obtained for this formula. SEM is used to illustrate the correlated mechanisms. This paper presents a promising tunable technology for large deformation sensors. Highlights • SEBS nanocomposites filled by CNTs and CB are prepared and their electrical conductivities are investigated experimentally. • The mechanisms of the decrease of mechanical hysteresis energy losses due to the replacement of CNTs with CB are explained. • The replacement of CNTs with CB brings a higher and more stable piezoresistive sensitivity and the mechanisms are explained. • Mathematical models of sensing mechanisms are proposed and all parameters are identified to explore the sensing mechanisms. • This study provides a guideline for tailoring the sensing behaviors using hybrid nanofillers for large deformation sensors. [ABSTRACT FROM AUTHOR]