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

Abstract

Liquid metal elastomer (LME)-that is, liquid metal particles dispersed in elastomer-is a soft material that has useful electric, dielectric, and thermal properties. Two issues with LME are sought to be addressed: 1) the dense liquid metal (LM) particles can settle before curing of the elastomer, and 2) the LM particles are separated by a thin layer of insulating elastomer and therefore require some "mechanical sintering" to break this layer to create conductive paths. These issues are addressed using an LME containing elastic particles (LMEP). Elastic polydimethylsiloxane particles (PPs) and LM particles jam to prevent particle settling. Meanwhile, the PPs reduce the loading necessary to create conductive paths, thus decreasing the density and cost relative to LME. Surprisingly, the particles percolate into conductive paths prior to curing the LMEP but not in LME. The dielectric constant, electrical conductivity, and thermal conductivity of LMEPs are investigated by changing the volume fraction of LM particles, polydimethylsiloxane prepolymer and PPs, and propose an LMEP with the optimal ratio. In addition, LMEP-based sensors and circuits are demonstrated for wearable electronics.

Self-Encapsulated Breathable Reduced Oxide Graphene-Coated Melamine Foam for Stress Sensing

“…However, after 300 cycles, the current variation rates stabilize. This phenomenon can be attributed to the Mullins effect, which is commonly observed in the deformation process of elastomers. ,− The SEB–rGO–MF–PS exhibits both elastic and plastic deformation during compression. In the initial compression process, the plastic deformation of the SEB–rGO–MF–PS cannot be neglected, leading to irreversible deformation that affects the integrity of the conductive path and results in a decrease in the current variation ratio.…”

“…Flexible pressure sensors have gained significant attention in human motion monitoring, − artificial electronic skin, − and wearable electronic devices. − The existing flexible pressure sensors can be categorized into piezoresistive, − capacitive, , piezoelectric, and triboelectric, according to different sensing mechanisms. Among them, piezoresistive sensors can convert pressure signals into electrical signals and have attracted extensive research interest due to their simple structure, convenient signal acquisition, rapid dynamic response, and cost-effectiveness. − To enhance the performance of piezoresistive pressure sensors, three-dimensional porous structures are usually introduced.…”

Zwitterionic Polymer Gel‐Based Fully Self‐Healable Ionic Thermoelectric Generators with Pressure‐Activated Electrodes

“…More-over, the gravitational sedimentation of LM microparticles leads to the separation of the LM microparticle-dominant side and the polymer-dominant side. [49][50][51][52][53] This phenomenon inhibits the permeation of the LM microparticle percolating layer to the nonconductive side, effectively separating the conductive and nonconductive sides. This feature was used to produce the desired electrical pathways (Figure 2a).…”

Nanoarchitectonics and Applications of Gallium‐Based Liquid Metal Micro‐ and Nanoparticles

“…The circuit prepared with this ink uses soft substrate and flexible design, so that it can withstand external forces such as bending, twisting and stretching without affecting its function. [82] (Figure 4h) In short, the emergence and development of GLM particle flexible circuits will promote the development of all walks of life.…”

“…drew inspiration from pomegranate seeds and mixed GLM particles with polydimethylsiloxane particles to produce GLM ink with high conductivity, high dielectric constant and super toughness. The circuit prepared with this ink uses soft substrate and flexible design, so that it can withstand external forces such as bending, twisting and stretching without affecting its function [82] . (Figure 4h) In short, the emergence and development of GLM particle flexible circuits will promote the development of all walks of life.…”