Thermal management of high temperature
systems through cooling
droplets is limited by the existence of the Leidenfrost point (LFP),
at which the formation of a continuous vapor film between a hot solid
and a cooling droplet diminishes the heat transfer rate. This limit
results in a bottleneck for the advancement of the wide spectrum of
systems including high-temperature power generation, electronics/photonics,
reactors, and spacecraft. Despite a long time effort on development
of surfaces for suppression of this phenomenon, this limit has only
shifted to higher temperatures, but still exists. Here, we report
a new multiscale decoupled hierarchical structure that suppress the
Leidenfrost state and provide efficient heat dissipation at high temperatures.
The architecture of these structures is composed of a nanomembrane
assembled on top of a deep micropillar structure. This architecture
allows to independently tune the involved forces and to suppress LFP.
Once a cooling droplet contacts these surfaces, by rerouting the path
of vapor flow, the cooling droplet remains attached to the hot solid
substrates even at high temperatures (up to 570 °C) for heat
dissipation with no existence of Leidenfrost phenomenon. These new
surfaces offer unprecedented heat dissipation capacity at high temperatures
(2 orders of magnitude higher than the other state-of-the-art surfaces).
We envision that these surfaces open a new avenue in thermal management
of high-temperature systems through spray cooling