Biomucilage‐Mediated Self‐Sintering Liquid Metal Ink for Robust Electronic Textiles With Soft‐Rigid Interfaces

The advancement of electronic textiles (e-textiles) depends on seamless integration of conductive materials that match the soft, breathable, and deformable nature of fabrics. However, achieving durable circuits on textiles remains challenging due to poor interfacial stability, limited stretchability, and inadequate wettability of conventional conductive materials. Liquid metal, while conductive and deformable, is difficult to adhere to textiles because of high surface tension and poor wettability. Here, we report a biomucilage-mediated liquid metal (bio-LM) ink that can be directly printed onto various textiles and, upon drying, autonomously self-sinters into highly conductive and robust circuits. The bio-LM ink forms strong bonds with textile, resulting in deformable interconnects that exhibit stable electrical performance, with resistance variations below 4% under repeated 15% stretching and across 20°C-50°C. Furthermore, we developed hole-like electrical interconnect (e-hole) structures that combine physical anchoring with chemical alloying between bio-LM and copper, creating solder-like, robust electrical junctions between soft textiles and rigid components. To verify its applicability, we demonstrate an integrated, closed-loop e-textile system capable of real-time muscle fatigue monitoring and on-demand heat therapy. This bio-LM ink establishes a new material foundation for robust, scalable, and skin-comfortable e-textiles, moving beyond conventional circuit integration toward breathable, elastic, and durable health-monitoring platforms.