Plant Cell-Mimetic Flexible Films for Integrated Solar-Thermal Regulation and Smart Sensing

The growing pressures from energy scarcity and climate change are driving the demand for personal thermal management materials that function efficiently at the body scale. However, integrating solar heat harvesting, leakage-free phase-change heat storage, and flexible sensing within a single soft material remains challenging, because these functions impose distinct, often conflicting, requirements on composition, phase distribution, and interfacial structure. Here, we report a plant-cell-inspired, one-step self-segregation strategy to construct a biomimetic Janus heterogeneous flexible film. During film formation, phase-change microcapsules spontaneously sediment to form a vacuole-like energy-storage bottom layer, whereas carbon nanotubes enrich at the upper surface, yielding a chloroplast-like continuous light-harvesting network. This vertical compartmentalization mitigates the filler-dilution trade-off commonly encountered in conventional composites. The resulting film achieves a photothermal conversion efficiency of 95.11% under 808 nm near-infrared irradiation and provides leakage-free latent-heat buffering. Introducing an interfacial regulator endows the film with high stretchability of 637.3% while allowing the film to retain its key functions after moisture exposure. In addition to thermal regulation, the integrated conductive and moisture-responsive pathways enable rapid humidity sensing with a response time of 165 ms for respiratory tracking, as well as stable strain sensing for real-time monitoring of human motion. This bioinspired compartmentalized architecture provides a strategy for wearable materials that integrate personal microclimate regulation with real-time health monitoring.