Gallium‐Based Liquid Metal Composites with Enhanced Thermal and Electrical Performance Enabled by Structural Engineering of Filler

Abstract

This article presents a systematic study on the impact of structural engineering of metallic copper fillers on the thermal and electrical performance of gallium‐based liquid metal composites. Herein, the copper fillers are directly blended into liquid metal matrix in air. Spherical copper filler is selected as a filler model to explore the influence of the size and amount of filler on the thermal conductivity of liquid metal composites. The significant enhancement in both thermal conductivity (≈301% enhancement, 54.2 W m−1 K−1, 51 vol%, 100 μm of spherical copper) and electrical conductivity (≈163% enhancement, 5.18 S μm−1) can be achieved by optimizing size, shape, and amount of the fillers. The as‐prepared copper filler–liquid metal composite shows distinguished heat dissipation performance in the thermal management of electronic devices. This work may also help to expand their usage in a wide range of applications, including thermal management systems, biomedical systems, and smart robotics.

Surface Optics and Color Effects of Liquid Metal Materials

“…An alkaline solution contains NaOH and NH 3 •H 2 O. [62,63] Based on the surface chemical activity of LMs, atomic-scale colorful metal films can be prepared using this strategy. [64,65] Furthermore, copper oxide particles can be directly attached to the surface of LMs by rolling.…”

Functional heterophasic liquid metals

“…Therefore, rigid metals such as Cu, Ag, Ni, and W are mixed LM to build heterophasic materials for thermal management. [22] Through mechanical mixing, the native gallium oxide (Ga 2 O 3 ) will break and reform continuously. The oxide helps LM and solid particles mix by creating a thin film that encases the particles.…”

“…Generally, high thermal conductivity is associated with fast heat dissipation, which is of great importance to avoid heat damage in electronics. Therefore, rigid metals such as Cu, Ag, Ni, and W are mixed LM to build heterophasic materials for thermal management [22] . Through mechanical mixing, the native gallium oxide (Ga 2 O 3 ) will break and reform continuously.…”

“…To address the above issues, research has been combining Ga-based LM with other metallic elements to tune the functionality. [20][21][22][23][24][25] The solid metals in the LMs (that forms heterophasic LMs in this review) not only address the above challenges but also bring new features into the heterophasic LMs. [26][27][28] We list several examples:…”

Liquid metal droplet motion transferred from an alkaline solution by a robot arm

“…[1][2][3][4][5][6] As emerging soft materials, gallium-based liquid metal alloys, such as eutectic EGaIn (75.5 wt% gallium and 24.5 wt% indium), have demonstrated enormous potential for developing high-performance smallscale devices in many important fields. [7][8][9][10][11] They have many unique physicochemical properties, such as high interface tension, 12 excellent thermal/electrical conductivity, [13][14][15][16][17] extreme flexibility, 4,18-20 low vapor pressure, 21 biocompatibility, 22 and low toxicity. 23,24 In addition, liquid metals (LMs) can be actuated under the methods of magnetic, 25,26 ultrasound, 20 optical, 27 and each method has its advantages in different applications.…”