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

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. In light of recent advancements in gallium-based liquid metal droplets (LMDs)-based electronics, this review outlines their unique properties, various preparation methods, and recent applications. Furthermore, existing challenges and future directions are discussed in this promising field.image