Bioinspired thermo-actuated thermoelectric/phase-change system for all-day power generation

The increasing global electricity demand underscores the urgent need for clean energy solutions. Thermoelectric materials, capable of converting waste heat into electricity, present a promising avenue. However, their efficiency is often compromised by intermittent heat sources. To address this, we propose a radial thermo-actuated thermoelectric/phase-change system inspired by the energy-conserving mechanism of the sun starfish’s wrist foot. This design employs shape memory alloy to optimize heat source utilization. The device autonomously opens to sustain a temperature gradient during sufficient heat supply and closes to minimize heat dissipation when the source is inadequate. Notably, the closed-state delays the hot-end temperature drop by ~ 1700 s, significantly reducing energy loss. Further integration with a photothermal-enhanced phase change material yields an all-day self-powered thermoelectric system. Daytime operation achieves a maximum temperature difference of 28.64 °C and an output voltage of 14.89 mV, while nighttime performance maintains an average temperature difference of 6.21 °C, ensuring stable heat supply. Our work introduces a scalable strategy for sustainable power generation in outdoor environments.