High-performance stretchable conductive film on complex microscale structures via spontaneous fusion of liquid metal.

Conformal fabrication of stretchable conductive film on micro-structured surfaces is important for flexible electronics. Existing methods based on material design and structural engineering suffer from limitations in stretchability, conductivity, and geometrical compatibility. Here, we propose a universal strategy for fabricating high-performance stretchable conductive film on complex micro-structured surfaces. By precisely controlling the interparticle liquid bridge force and the critical rupture strength of liquid metal (LM) particle shells, the spontaneous fusion of LM particles is realized to form high-performance stretchable conductive film without requiring extra activation processes. Driven by the Laplace pressure difference, the stretchable conductive film can be conformally deposited on arbitrary 3D microstructures such as high-aspect-ratio vertical interconnect accesses. This capability enables the development of stretchable multilayer electronic systems with high stability even under dynamic strain. Moreover, the thin film allows the exposure of sweat pores and hair when forming seamless coupling with human skin, enabling highly effective electrical stimulation and high-fidelity electrophysiological monitoring with sweat permeability and imperceptibility. This work establishes a universal approach for integrating high-performance stretchable conductors onto complex 3D architectures, bridging material-level innovation with system-level implementation for wearable electronics and bio-integrated systems.