Self‐Adhesive Liquid Metal Channel Patch with Tip‐Guided Conformal Coupling and Leakage Suppression for Skin Bioelectronics

Abstract Skin‐interfacing electrodes are essential for wearable bioelectronics, yet conventional gel‐ and dry‐type electrodes often suffer from dehydration, poor skin conformity, irritation, and delamination during motion, limiting their long‐term performance. Here, a self‐attachable liquid metal channel (S‐LMC) patch is presented that integrates open‐bottom Galinstan microchannels and micropillar arrays, both featuring re‐entrant geometries for enhances skin adhesion and leakage suppression. A via‐hole interconnect enables direct vertical signal transmission, eliminating the need for bulky wiring and facilitating compact integration. The patch achieves strong, reusable skin adhesion (>60 kPa), low contact impedance (7.35 kΩ·cm ² at 10 Hz), and minimal skin irritation. Compared to commercial Ag/AgCl gel electrodes, the S‐LMC patch exhibits >5× lower impedance, >2× higher ECG signal fidelity (20.23 dB vs. 9.03 dB under motion), and >2.4× higher long‐term adhesion after 7 days. Its re‐entrant microarchitecture also improves Galinstan confinement, achieving >2× higher critical pressure for leakage. These features enable motion‐resilient biosignal monitoring and scalable system integration, establishing the S‐LMC patch as a promising platform for next‐generation skin‐conformal bioelectronic interfaces.