Transient Emulsion-Assisted Fabrication of Liquid Metal Microsphere Arrays for Mechanically Adaptive Anisotropic Conductive Packaging

Liquid metal (LM) microsphere arrays hold great promise as adaptive conductive frameworks for next-generation flexible electronics. However, the spatial arrangement of micronano LM droplets poses a longstanding challenge to their practical application due to their inherent ultrahigh surface tension. Here, we introduce a transient emulsion-assisted self-assembly and fusion strategy that turns surface tension from a barrier into a driving force for ordered LM microsphere formation and precise positioning. The resulting LM microspheres exhibit dynamic interfacial conduction, enabling excellent mechanical adaptability under deformation. Embedded into a thermally responsive polymer matrix, the fabricated LM microsphere-arrayed anisotropic conductive film (ACF) achieves an ultralow contact resistance (0.303 mΩ/mm², 96% lower than conventional ACFs) and stable performance under cyclic loading. Demonstrated in packaging flexible chip-LED arrays with stretchable circuits, this approach ensures both mechanical resilience and electrical reliability. This work offers a scalable pathway toward high-performance, compliant interconnects for future soft electronic systems.