Condensation Droplet Sieve

TL;DR

This paper introduces a condensation droplet sieve using microscale lattice structures coated with superhydrophobic material, enabling nearly all droplets to spontaneously jump off, significantly improving anti-fogging and heat transfer performance.

Contribution

The study presents a novel microscale lattice design that ensures droplet detachment with controlled size, surpassing current methods in efficiency and droplet size confinement.

Findings

Droplets jump off the surface with 100% probability once exceeding a certain size.

Maximum droplet radius confined to 16 μm, residual volume to 3.2 nl/mm².

The jumping efficiency is due to tolerance of coalescence mismatch and droplet isolation.

Abstract

Large droplets emerging during dropwise condensation impair surface properties such as anti-fogging/frosting ability and heat transfer efficiency. How to spontaneously detach massive randomly distributed droplets with controlled sizes has remained a great challenge. Herein, we present a general solution called condensation droplet sieve, through fabricating microscale thin-walled lattice (TWL) structures coated with a superhydrophobic layer. Growing droplets were observed to jumped off this TWL surface with 100% probability once becoming slightly larger than the lattices. The maximum radius and residual volume of droplets were strictly confined to 16 {\mu}m and 3.2 nl/mm2 respectively, greatly surpassing the current state of the art. We reveal that this extremely efficient jumping is attributed to the large tolerance of coalescence mismatch and effective isolation of droplets between neighbouring lattices. Our work provides a new perspective for the design and fabrication of high-performance anti-dew materials.