MWCNT-reinforced silicone's dual response to human and mechanical motion: Exploring strain sensing behavior and practical applications

Abstract

This study investigates the human motion sensing capabilities of silicone rubber (SR) composites reinforced with multi-walled carbon nanotubes (MWCNTs). It focuses on assessing the responsiveness of the composites to both compressive and tensile deformations, replicating motions from machines to human movements. The analysis underscores the enhanced sensitivity of the 3 parts per hundred (phr) compressive sample, with gauge factors of 7.5 and 14.44 at distinct linear ranges under 30% strain. During forefinger and thumb pressing, the relative change in resistance was 160 and 350, respectively. Additionally, the study examines the 5 phr sample, revealing a significant 346.67% increase in relative resistance changes during the initial cyclic loading phase under 30% tensile deformation compared to the compression sample. The mechanical properties are also evaluated, showing the 5 phr compressive sample possessing a compressive modulus 180.09% higher than the modulus of the unfilled specimen (1.246 MPa), along with a hysteresis loss of 37.24 kJ. Furthermore, the tensile modulus of the 5 phr specimen exceeds that of the unfilled rubber by 218.84%. The developed composites hold promise for creating sensors capable of tracking athletes' movements in real time, offering immediate performance feedback and post-processing analysis. Moreover, these materials could contribute to the design of rehabilitation devices aimed at assisting individuals with hand injuries in regaining their agility and mobility.