From Droplets to Devices: Recent Advances in Liquid Metal Droplet Enabled Electronics

Abstract

Liquid metals, particularly non‐toxic gallium‐based alloys, have emerged as promising materials for future soft electronics due to their unique properties, including fluidity, excellent electrical and thermal conductivities, and surface reactivity. They demonstrate adaptability, responsivity, and self‐healing abilities, offering a platform for innovative electronic devices. Embodied in a droplet form factor, gallium‐based liquid metal droplets (LMDs) combine the traits of liquid metals with the advantages of miniaturized structures, including high surface tension, high surface area, high mobility, and surface functionalization. This review discusses the inherent properties of LMDs, which have driven substantial research interest across various fields, such as sensors, robotics, electronic circuits, energy harvesters, drug delivery, and microfluidics systems, among others. Effective fabrication and processing techniques are detailed for LMDs, illustrating their role in applications previously challenging with conventional materials, such as reconfigurable, self‐healing, and transient electronics. Existing challenges and future directions in this growing field are discussed. This extensive review seeks to further the understanding of LMDs and their potential, offering a roadmap for their journey from a niche interest to a key material in various electronic devices.

Gallium-based liquid metals as reaction media for nanomaterials synthesis

“…The oxide skin significantly alters the physical and chemical properties of Ga-based LMs, affecting their surface chemistry, wetting behavior and rheological properties. 36 Furthermore, the oxide skin also enhances the adhesion of the metal substrate, allowing it to firmly adhere (or ‘wet’) more efficiently with many substrates, particularly like glass, quartz, SiO 2 /Si wafers or polyimide films. 37 The non-polar and mobile nature of the parent metal also make the oxide skin on the surface less attractive, allowing for easy transfer of the oxide layer to desired substrates or its layering into a colloidal suspension (Fig.…”

Electronic Skin for Health Monitoring Systems: Properties, Functions, and Applications

“…Due to their good conductivity, fluidity, and inherent deformability, LMs have emerged as conductive materials for eskins. [193][194][195][196][197] As the LM is in a liquid state at room temperature, it is generally necessary to be combined with flexible substrates for [186] Copyright 2023, American Chemical Society. b) Photograph of the patterned rGO/PDMS films.…”

Finite-size effect on the percolation and electromechanical behaviors of liquid metal particulate composites

“…[15][16][17] Potential applications of LMPCs have been reported for soft electronics, soft robotics, sensing, actuation, and electromagnetic shielding. 1,10,18 An unfavorable feature of LMPCs is that they are electrically insulated upon synthesis due to the native surface oxide surrounding LM particles. A subsequent mechanical sintering process 7,19 is usually necessary to activate the conductance.…”

“…15–17 Potential applications of LMPCs have been reported for soft electronics, soft robotics, sensing, actuation, and electromagnetic shielding. 1,10,18…”