Figueira Cheese‐Inspired Hierarchical Nanocomposites: Combining Ultralow Percolation and Breathability Toward Full‐Lifecycle Circular Epidermal Electronics

ABSTRACT Simultaneously achieving high electrical conductivity, mechanical compliance, and breathability remains a critical bottleneck for epidermal electronics. Conventional composites typically suffer from trade‐offs between filler loading and softness while often lacking necessary permeability or recyclability. Here, we report a sustainable phase‐separated nanocomposite mimicking the hierarchical porous texture of Figueira cheese. Our synthesis leverages distinct solvent solubility and volatility differences to orchestrate a kinetic phase separation, driving silver nanowires to self‐assemble along a porous elastomer skeleton. This architecture decouples electrical performance from mechanical constraints, exhibiting a high conductivity of 2.8 × 10 5 S m − 1 and a water vapor transmission rate exceeding 1200 g m − 2 day − 1 . Additionally, its Young's modulus of 0.45 MPa (Shore A hardness 28) ensures intimate conformity to skin. Featuring an ultralow percolation threshold of 0.00119 vol% and exceptional strain insensitivity, the nanocomposite enables stable Joule heating and electrophysiological monitoring. Crucially, the material supports efficient closed‐loop recycling, recovering both elastomer and fillers. Even after 4 life cycles, it retains over 75% conductivity and fully preserves functionality for high‐fidelity electrophysiological monitoring. This work establishes a paradigm for sustainable, high‐performance epidermal electronics.