Transportable, Endurable, and Recoverable Liquid Metal Powders with Mechanical Sintering Conductivity for Flexible Electronics and Electromagnetic Interference Shielding

Abstract

Liquid metals (LMs, e.g., EGaIn) promise a vast potential in accelerating the development of flexible electronics, smart robots, and wearable and biomedical devices. Although a variety of emerging processing methods are reported, they suffer several risks (e.g., leakage, weak adhesion, and low colloidal and chemical stability) because of their excellent fluidity, high surface tension, and rapid oxidation. Herein, liquid metal powders (LMPs) are fabricated based on a versatile method by vigorously stirring EGaIn with nonmetallic or organic particles through interfacial interactions. During the mixing process, EGaIn microdroplets are wrapped with a nonmetallic or an organic shell by electrostatic adsorption, and a more sticky oxide layer is constantly generated and then broken owing to the shearing friction. These transportable powders exhibit superior stability under extreme conditions (e.g., water and high temperature), being capable of recovering electrical conductivity and strong adhesion on different substrates upon mechanical sintering. A flexible, robust, and conductive coating can be constructed via swabbing with an integrated Joule heating effect and excellent electromagnetic interference shielding performances, and it is applicable in flexible wearable electronics, microcircuits, and wireless power transmission systems.

Versatile chewed gum composites with liquid metal for strain sensing, electromagnetic interference shielding and flexible electronics

“…Liquid metals (e.g., EGaIn, Ga/In at 75 : 25 wt/wt) with good fluidity and high electrical and thermal conductivity, have been utilized in flexible electronics and sensors and as electromagnetic interference-shielding materials. [22][23][24][25][26] However, leakage resulting from their good fluidity can lead to serious risks of short-circuiting and corrosion, 22 which pose great challenges during handling and processing. Besides, the ultrahigh surface tension of liquid metals (i.e., 624 mN m À1 for EGaIn) makes it difficult to achieve a stable interface of the liquid metal with other materials (e.g., composite matrix, patterning substrates).…”

Copper-Coordinated Cellulose Fibers for Electric Devices with Motion Sensitivity and Flame Retardance

“…5 Flexible fibers that can undergo bending, twisting, and stretching with good durability as well as have high conductivity and comfort are indispensable for constructing flexible wearable electronics. 6 Typically, conductive fibers are present in conductive components for electric conduction, such as silver, 7 copper, 8 graphene, carbon nanotubes (CNTs), 9,10 MXene, 11 liquid metals, 12,13 polypyrrole (PPy) 9 and polyacrylonitrile (PAN). 5 These conductive materials could be composited into fibers by co-mingled spinning (e.g., electrospinning and wet spinning), 14,15 dip-coating, 16,17 chemical plating, 18 vapor deposition, 19 and in situ polymerization.…”

“…Typically, conductive fibers are present in conductive components for electric conduction, such as silver, copper, graphene, carbon nanotubes (CNTs), , MXene, liquid metals, , polypyrrole (PPy) and polyacrylonitrile (PAN) . These conductive materials could be composited into fibers by co-mingled spinning (e.g., electrospinning and wet spinning), , dip-coating, , chemical plating, vapor deposition, and in situ polymerization .…”

Room‐Temperature Liquid Metals for Flexible Electronic Devices

“…Initially, eutectic gallium-indium and Galinstan were coated onto substrates such as dense polymer films or textiles to create stretchable and flexible conductive traces. [12] Second, micro-and nanosized RT-GaLMs can be used as a conductive functional ink to print circuit patterns on soft substrates such as elastomers and polymers, as well as functional fillers in the polymer matrix, allowing the development of flexible and reconfigurable electronic circuits. [13,14] Third, RT-GaLMs can be integrated in polymer matrix used as a sensing element in pressure, strain, gas, and moisture sensors due to their high electrical conductivity and functionality.…”