Cyclic mechanical behaviours of polydimethylsiloxane / multi-walled carbon nanotube micro-composites sensor: Effects of strain range and strain rate

PDMS (polydimethylsiloxane) / MWCNT (multi-walled carbon nano tube) micro-composites (PMMCs), which ensures both electrical conductivity and stretchability as well as load-bearing capacity, emerge as a promising candidate for electrode material in the field of wearable sensors. This study focuses on investigating the tensile behaviour and mechanical property changes of PMMC strain sensors under cyclic loading, taking into account a dynamic usage environment of wearable sensors. This research provides academically novel insights by thoroughly analysing both the independent and combined effects of test variables, such as tensile strain range, strain rate, and the mass fraction of MWCNTs within PMMCs, comprehensively considered. Furthermore, based on the stress-strain data obtained from the tests, nonlinear curve fitting is conducted to determine the optimal hyperelastic material model for simulating the nonlinear tensile behaviour of PMMC strain sensors. The summarised hyperelastic material coefficients can be utilised to simulate the cyclic tensile behaviour of wearable sensors to be developed in the future.