Enhanced Liquid Metal‐Hydrogel Interface for Fabricating a High‐Precision Implantable Cardiac Pacemaker

Implantable bioelectronic devices demonstrate immense potential in health monitoring and therapeutic interventions, yet encounter formidable challenges in achieving biocompatibility and interfacial stability within complex biological environments. This study proposes a novel liquid metal‐hydrogel bonding strategy based on Cabrera–Mott oxidation kinetics regulation, which significantly enhances the printability of liquid metals on biocompatible hydrogel substrates through interfacial tension reduction and accelerated surface oxidation. Experimental findings revealed a 26.25% reduction in contact angle and a printing resolution improvement to 200 µm while maintaining superior electrical conductivity (3.83 × 10 5 S/m). Leveraging this advancement, we developed a flexible cardiac pacemaker integrating wireless energy transmission, pulse circuitry, and electrostimulation modules, which successfully achieved stable cardiac rhythm modulation in murine heart failure models. Histopathological analyses further corroborated the device's biosafety profile. This study presents a promising strategy for miniaturized implantable bioelectronics design and biointerface optimization, offering valuable insights for the development of future personalized bioelectronic systems.