All-Polyimide-Mediated Liquid Metal Assembly on Aerogels for Breathable and Robust Electronic Skins

Constructing breathable electronic skins (E-skins) that maintain high electrical performance remains a formidable challenge due to the difficulty of establishing robust conductive networks on fragile porous substrates. To address this issue, a robust bio-interface based on an ultralight polyimide aerogel that combines high vapor permeability (1700 g m^{- 2} day^{- 1}) with intrinsic hydrophobicity (>123°) is developed. Leveraging the superior thermal stability (up to 460°C), a liquid metal particle ink encapsulated by polyamic acid shell is activated through mild thermal treatment at 140°C. The resulting imidization-induced contraction generates compressive stress to rupture insulating oxide layers and achieve a high electrical conductivity of 8.17 × 10⁵ S m^{- 1}. This architecture employs an isotropic open-cell framework that confines the ink to the surface while maintaining interconnected three-dimensional (3D) pathways for lateral gas transport, thereby ensuring sustained breathability regardless of conductive layer coverage. Strong interfacial bonding through chemical coordination and mechanical interlocking enables negligible resistance variation over 200 000 deformation cycles and reliable underwater functionality. These synergistic advantages support diverse applications including conformal Joule heating, magnetic field sensing, and high-fidelity electrophysiological monitoring during intense motion, establishing a versatile platform for next-generation wearable healthcare.