Segregated and Non-Settling Liquid Metal Elastomer via Jamming of Elastomeric Particles

摘要

Liquid metal elastomer (LME)-that is, liquid metal particles dispersed inelastomer—is a soft material that has useful electric, dielectric, and thermalproperties. Two issues with LME are sought to be addressed: 1) the denseliquid metal (LM) particles can settle before curing of the elastomer, and2) the LM particles are separated by a thin layer of insulating elastomer andtherefore require some “mechanical sintering” to break this layer to createconductive paths. These issues are addressed using an LME containingelastic particles (LMEP). Elastic polydimethylsiloxane particles (PPs) andLM particles jam to prevent particle settling. Meanwhile, the PPs reduce theloading necessary to create conductive paths, thus decreasing the densityand cost relative to LME. Surprisingly, the particles percolate into conductivepaths prior to curing the LMEP but not in LME. The dielectric constant,electrical conductivity, and thermal conductivity of LMEPs are investigatedby changing the volume fraction of LM particles, polydimethylsiloxane prepolymerand PPs, and propose an LMEP with the optimal ratio. In addition,LMEP-based sensors and circuits are demonstrated for wearable electronics.