Coupling droplets/bubbles with a liquid film for enhancing phase-change heat transfer

Evaporation, boiling, and condensation are fundamental liquid-vapor phase-change heat transfer processes and have been utilized in many conventional and emerging energy systems. Recent advances in the manipulation of interface wetting and heterogeneous nucleation using micro/nano-structured surfaces have enabled exciting two-phase flow dynamics and heat transfer enhancement. However, independently manipulating droplets, bubbles, or liquid films through surface modification has encountered bottlenecks. In this Perspective, we discuss an emerging strategy where droplets/bubbles are coupled with a liquid film to control fluid dynamics for minimizing the thermal resistance between the liquid-vapor interface and solid substrate, thus significantly enhancing the heat transfer performance beyond the state of the art.