Surface and Interface Engineering in Gallium-Based Liquid Metals

Gallium-based liquid metals (LM) combine metallic conductivity, fluidity, and self-limiting oxide layers, showing exceptional promise for flexible electronics, energy storage, catalysis, and microwave shielding. However, performance limitations arise from interfacial challenges in LM composites, including phase incompatibility and interfacial instability caused by gallium oxide layers and incorporated components. Additional hurdles include high surface tension, complicating shape control. This review examines interface engineering strategies to address these limitations through three approaches: tailoring interfacial modifications, structural design, and reactive interfaces for functional enhancement. Following an overview of core properties and oxidation behaviors inherent to Ga-based LMs, interface engineering in LM composites is systematically analyzed across two material categories: LM-organic interfaces with dynamic molecular interactions, and LM-inorganic interfaces governed by metallurgical bonding. For each category, unique interfacial characteristics and corresponding engineering methodologies are discussed. Advanced applications demonstrate how optimized interfaces enhance electrical/thermal transport, mechanical compliance, and environmental stability. The analysis offers guidance for advancing LM material development in this evolving field, emphasizing that interfacial control represents a critical pathway to unlock their full potential across emerging technologies.