Dynamic Defrosting on Nanostructured SuperhydrophobicSurfaces.

Watersuspended on chilled superhydrophobic surfaces exhibits delayedfreezing; however, the interdrop growth of frost through subcooledcondensate forming on the surface seems unavoidable in humid environments.It is therefore of great practical importance to determine whetherfacile defrosting is possible on superhydrophobic surfaces. Here,we report that nanostructured superhydrophobic surfaces promote thegrowth of frost in a suspended Cassie state, enabling its dynamicremoval upon partial melting at low tilt angles (<15°). Thedynamic removal of the melting frost occurred in two stages: spontaneousdewetting followed by gravitational mobilization. This dynamic defrostingphenomenon is drivenby the low contact angle hysteresis of the defrosted meltwater relativeto frost on microstructured superhydrophobic surfaces, which formsin the impaled Wenzel state. Dynamic defrosting on nanostructuredsuperhydrophobic surfaces minimizes the time, heat, and gravitationalenergy required to remove frost from the surface, and is of interestfor a variety of systems in cold and humid environments. [ABSTRACT FROM AUTHOR]