Canine Tongue-Inspired Superspreading-Enhanced Cross Scale-Coupled Evaporation for Thermal Management

Overheating is a major cause of device failure. Thin-film evaporative cooling leverages the latent heat of liquid phase change, but its performance is often governed by the balance between interfacial liquid supply and interfacial mass-transfer kinetics. The canine tongue maintains a continuously wetted surface through rapid saliva replenishment and evaporation during thermoregulation. Here, previously unreported nanocilia on the tongue surface of the Beagle ( Canis lupus familiaris) are identified. These nanocilia coat microscale papillae, revealing a naturally evolved micro–nano hierarchical architecture. Inspired by this architecture, a bioinspired cross-scale continuous surface (BioCCS) integrating microgrooves and nanowires is developed. Microgrooves promote stable liquid spreading, while nanoscale confinement modulates interfacial water interactions and weakens interfacial hydrogen bonding, together establishing a cross-scale coupled evaporation mechanism (CCEM) bridging micro–nano–molecular scales. Tested at 80 ° C, a temperature relevant to device reliability, BioCCS achieves an evaporation rate of 31.36 kg h –1 m –2 , enabling a self-sustained passive cooling system with a 150% enhancement in heat dissipation compared with an unmodified surface. These results provide a concept for autonomously sustained phase change cooling under subboiling conditions.