Liquid metal particles as versatile building blocks: fabrication, design principles, and multifunctional applications

Liquid metals (LMs), particularly gallium-based alloys, have attracted increasing interests as a unique materials platform spanning soft and hard matter. When transforming from bulk LM to micro/nanoscale particles, LMs undergo a fundamental transition: the formation of a metal-oxide core-shell structure imparts interfacial stability, tunable chemistry, and dynamic reconfigurability inaccessible to bulk LMs. The LM particles not only mitigate intrinsic drawbacks of bulk LMs such as high surface tension, poor substrate adhesion, and uncontrolled spreading but also unlock new functionalities through scale effects, interfacial engineering, and external-field responsiveness. As building blocks, LM particles exhibit high specific surface area, programmable wettability, and facile dispersion, enabling multifunctional integration across fields ranging from soft robotics and stretchable electronics to catalysis, energy storage, and biomedicine. This review systematically outlines fabrication strategies that govern LM particle formation, emphasizing how processing parameters control size, composition, and surface state. Building on a comparative, application-oriented framework, the review innovatively clarifies where LM particles-based structure offers decisive advantages over bulk LMs across soft actuation, stretchable electronics, energy-related systems, catalysis, thermal management, solar interfacial evaporation, synthesis, and biomedicine. Importantly, transferable design principles are distilled within each application. Finally, persistent challenges in long-term interfacial stability, oxide control, and scalable manufacturing are discussed, together with practical pathways toward robust, intelligent, and multifunctional LM particle-based systems.