Synergistic modulation of solar and thermal radiation driven by mechano-thermochromism

Solar heating and radiative cooling technologies are pivotal for building energy conservation, while conventional coatings with quasi-static radiative properties are limited to either heating or cooling, hindering year-round efficiency. Here, we present an all-season smart coating that dynamically modulates solar-thermal radiation via mechano-thermochromism. The coating consists of a VO₂/BaF₂ nanograting on a PDMS substrate with a crumpled metal layer, enabling adaptive control of radiative properties. Using Rigorous Coupled Wave Analysis and Genetic Algorithm optimization, we numerically demonstrate absorptance and emittance tunability of 0.376 and 0.795, respectively. The underlying mechanism is governed by Fabry–Pérot resonance, specifically, PDMS stretching primarily regulates absorption, while the VO₂ phase transition controls emittance. At an ambient temperature of 280 K, the coating achieves a tunable net heat flux of ∼400 W/m² at the VO₂ critical point. This work provides a promising strategy for adaptive thermal regulation, advancing the practical deployment of smart coatings for energy-efficient buildings.