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

Zeng, Wei; Li, Yunxiao; Gan, Yuefeng; Luo, Xianfeng; Xing, Yun; Zhu, Zhongpeng; Tian, Ye; Jiang, Lei · ACS Nano · 2026

basic_science · Level V

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Abstract

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 (<i>Canis lupus</i> 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<sup>-1</sup> m<sup>-2</sup>, 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.