Direct integration of stretchable modules for implantable bioelectronics

Stretchable implantable bioelectronics enable mechanically compliant operation on deforming tissues, yet system-level integration remains challenging. Integrating electrode, interconnect, and circuit modules often requires additional adhesive or conductive bonding layers at their junctions, complicating fabrication and potentially compromising mechanical robustness. Here, we introduce an interlayer-free integration strategy that combines self-healing polymer substrates with liquid metal conductors. Healing-mediated interfacial reconstruction of the polymer substrates forms mechanically cohesive junctions within minutes of contact, while fluidic reconnection of the liquid metal establishes electrical continuity between modules. These junctions exhibit an interfacial toughness of 600 N m − 1 and maintain electrical continuity at tensile strains of approximately 1,000%. Electrode impedance and charge storage capacity show limited changes after repeated stretching. Self-healing between overlapping regions of the polymer substrate further secures electrodes wrapped around the heart and sciatic nerve. The assembled wireless systems deliver cardiac and sciatic nerve stimulation in rat models, demonstrating their stable operation in vivo. Together, these results extend self-healing beyond damage repair to system assembly and tissue fixation, enabling stretchable bioelectronics to function on dynamically moving organs.