Study on boiling characteristics of liquid crystal elastomer surfaces with thermally adaptive wettability

Boiling heat transfer is one of the most effective approaches for addressing thermal management challenges in high-power devices. However, different stages of the boiling process impose distinct requirements on surface wettability, creating an urgent need for surfaces capable of adaptively regulating their wettability in response to boiling conditions. A disulfide bond-based liquid crystal elastomer was synthesized using a two-step crosslinking method, and then integrated with a copper substrate. Microstructures were formed on the surface through hot-pressing. By leveraging the shape-memory effect of the liquid crystal elastomer material together with the influence of microstructures on surface wettability, a temperature-adaptive wettability surface was fabricated, enabling a tunable contact angle from 96° at low temperature to 74° at high temperature. The boiling characteristics of an adaptively wettable surface under different temperatures and heat fluxes were investigated experimentally, including bubble and liquid behavior and boiling curves. The results indicate that at low heat fluxes, the adaptive surface promotes bubble nucleation and reduces superheat, while at high heat fluxes, it enhances liquid supply and delays dryout, thereby increasing the critical heat flux. Compared with the smooth liquid crystal elastomer surface, the adaptive surface achieved up to a 6.5 enhancement in the heat transfer coefficient, the feasibility of regulating boiling heat transfer using an adaptive surface was verified.