Desert beetle-inspired wettability-engineered surface for synergistic enhancement of boiling heat transfer and...

Industrial equipment is confronted with escalating challenges, specifically inefficient high-temperature boiling heat transfer and severe scaling on heating surfaces. Conventional single-wettability superwetting surfaces (either superhydrophobic (SHPO) or superhydrophilic (SHPI)) cannot address bubble dynamics regulation and scale inhibition simultaneously. Herein, this work presents a desert beetle-inspired wettability-engineered surface (DWES) with alternating SHPO and SHPI regions, which achieves synergistic enhancement of boiling heat transfer and anti-scaling performance. The DWES mimics the heterogeneous wettability of desert beetles but adopts an opposite control mode. Specifically, desert beetles use hydrophilic regions to retain droplets and hydrophobic regions to transport them. In contrast, the DWES uses low-energy SHPO regions as preferential bubble nucleation sites and high-energy SHPI regions to accelerate bubble detachment. The anti-scaling principle is closely related to this bubble behaviour: frequent bubble detachment induced by SHPI regions scours the surface, effectively preventing mineral ions from adsorbing and aggregating, thereby inhibiting the formation of dense, hard scale layers. Meanwhile, this bubble detachment also reduces thermal resistance, further enhancing heat transfer efficiency. Under industrial boiler heat flux, the DWES outperforms traditional SHPI surfaces, with a 4% higher HTC and an approximately 87% reduction in scaling. It also maintains stable performance across a wide range of salt concentrations and temperatures. This study clarifies the link between bionic patterning and performance, providing an effective strategy for developing anti-scaling, energy-saving boiler coatings.