Laser-Patterned Liquid Metals: From Interfacial Challenges to Programmable Soft Electronics

Gallium-based liquid metals have emerged as promising materials for soft and stretchable electronics because they combine metallic conductivity with fluidic deformability, conformal contact, and interfacial adaptability. However, these same attributes also make them difficult to pattern with high fidelity, as their behavior is governed by coupled interfacial phenomena including high surface tension, native oxide formation, substrate-dependent wettability, and dynamic morphological reconfiguration. In this Perspective, we argue that laser processing is particularly well suited to address these challenges because it operates directly at the local interface where liquid metal behavior is determined. By selectively rupturing oxide shells, modulating wetting, controlling morphology, and tuning phase evolution with high spatial and temporal precision, laser irradiation enables liquid metals to transition from difficult-to-pattern conductors into programmable functional materials. We discuss recent advances in laser-patterned liquid metals for semitransparent electrodes, infrared-active surfaces, freestanding 3D conductors, stretchable interconnects, cuffless bio-signal monitoring, and environmentally robust wearable electronics. These examples demonstrate that laser processing can do more than restore conductivity; it can define multifunctional device architectures with tailored electrical, optical, thermal, and mechanical properties. Looking ahead, the field should move toward mechanism-informed design, scalable manufacturing, multifunctional integration, and application-driven material programming for next-generation soft electronic systems.