Modeling electromechanical coupling of liquid metal embedded elastomers while accounting stochasticity in 3D percolation

Abstract

Liquid metal embedded elastomers (LMEEs) have attracted interest from researchers on account of their combination of low elastic modulus, high flexibility, and tunable electrical and/or thermal conductivity. One interesting feature of LMEEs is that their electrical resistance remains constant when stretched, which is desirable in many real-world applications. This work aims to investigate this unique electromechanical coupling behavior of LMEEs with three-dimensional deterministic and statistical modeling. We first performed finite element analysis (FEA) of the electromechanical coupling response of a percolated liquid metal droplet repeating in the conductive network. Next, we modeled the internal conductive network of LMEE as a simple cubic structure and introduced stochasticity in representing the droplet–droplet connectivity. This combined approach allows us to calculate relative changes in resistance with stretch that are in reasonable agreement with experimental findings. Our analysis provides new theoretical insights that can guide efforts to tailor the electromechanical coupling behavior of LMEEs.