Thermogalvanic Hydrogel for Synchronous Evaporative Cooling and Low-Grade Heat Energy Harvesting.

Efficient heat removal and recovery are two conflicting processes that are difficult to achieve simultaneously. Here, in this work, we pave a new way to achieve this through the use of a smart thermogalvanic hydrogel film, in which the ions and water undergo two separate thermodynamic cycles: thermogalvanic reaction and water-to-vapor phase transition. When the hydrogel is attached to a heat source, it can achieve efficient evaporative cooling while simultaneously converting a portion of the waste heat into electricity.

Promoting Energy Efficiency via a Self-Adaptive Evaporative Cooling Hydrogel.

High temperature brings adverse impacts on the energy efficiency, and even destroys a semiconductor device. Here, a novel and cost-effective strategy is proposed to boost the energy efficiency of semiconductor devices by using the self-adaptive evaporative cooling of a lithium- and bromine-enriched polyacrylamide hydrogel. Water inside the hydrogel can quickly evaporate to dissipate the waste heat generated by the nugatory carrier transport in the P-N junction.