Mechanical and Functional Tradeoffs in Multiphase Liquid Metal, Solid Particle Soft Composites

Abstract

Soft materials with high thermal conductivity are critical for flexible electronics, energy storage and transfer, and human-interface devices and robotics. However, fundamental heat transport limitations in soft and deformable materials present significant challenges for achieving high thermal conductivity. Here, a systematic study of soft composites with solid, liquid, and solid-liquid multiphase metal fillers dispersed in elastomers reveals key strategies to tune the thermal-mechanical response of soft materials. Experiments supported by thermodynamic and kinetic modeling demonstrate that multiphase systems quickly form intermetallics that solidify and degrade mechanical response with modest gains in thermal conductivity. In contrast, liquid metal 1 This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Switchable Adhesives for Multifunctional Interfaces

“…Discretization of interfaces can allow for more efficient transport, which when coupled with multifunctional structures with advanced thermal or transport properties, [205][206][207] can provide synergistic effects. As mentioned, heat transport and diffusion are fundamental limitations for thermal and fluidic-based triggers, respectively.…”

“…As mentioned, heat transport and diffusion are fundamental limitations for thermal and fluidic-based triggers, respectively. Discretization of interfaces can allow for more efficient transport, which when coupled with multifunctional structures with advanced thermal or transport properties, [205][206][207] can provide synergistic effects. Multimaterial printing can create material and structural layouts, providing design tools for well-controlled interfacial properties.…”

Liquid Metal–Based Soft Microfluidics

“…Therefore, potential applications of such a composite are biologically inspired robots and thermal interface materials (TIM) . Furthermore, Tutika et al studied the thermal conductivity of soft composites with solid, liquid, and solid–liquid multiphase metal fillers dispersed in elastomers – a schematic illustration is shown in Figure c. Although the thermal conductivity of solid metal particles is obviously higher than that of liquid metal, higher thermal conductivity (up to k = 6.7 ± 0.1 W m −1 K −1 ) was obtained for liquid metal inclusions, which was ascribed to the significantly higher loadings (φ = 80%) of the liquid metal while still being an elastic, as shown in Figure d.…”

“…The inset shows a magnification of low thermal conductivity values. Reproduced with permission . Copyright 2018, John Wiley and Sons.…”

A Novel Conductive Core–Shell Particle Based on Liquid Metal for Fabricating Real‐Time Self‐Repairing Flexible Circuits

“…In the past, liquid metal micro/nanoparticles (LMPs) were prepared by sonication,15,16 microchannel,8,17 or grinding19,20 to fabricate flexible circuit with excellent durability. Compared to bulk liquid metals, LMPs have its own advantages in fabricating flexible electronics.…”