Condensation control on biphilic jumping droplet surface

Controlling condensation is crucial for applications such as thermal management or to maintain optical surface transparency in humid conditions. Condensation behavior can be controlled by surface structure: on nanoscale hydrophobic structures, droplets can jump out of the surface upon merging [1]. Making the nanostructures conical further amplifies the anticondensation property, as the jumping probability rises close to 100% [2]. The constant condensation removal allowed by the jumping mechanism significantly increases the heat transfer performance of the surface [3] and can be further improved by promoting nucleation with micrometric hydrophilic patterns [4]. Condensation removal limits the droplet size to the distance to its nearest neighbor which helps maintaining a good optical transparency. However, this distance depends on the random nucleation process and droplets nucleating far from each other will cover a large surface area before jumping which is detrimental for optical properties. In this presentation, we spatially control nucleation with biphilic patterns on a jumping droplet surface and study how it affects the condensation properties such as surface coverage, volume, or lifetime.

References

[1] Boreyko, J. B. & Chen, C. H., Physical review letters, 103(18), 184501, 2009.

[2] Mouterde, T. et al. Nature Materials, 16(6), 658-663, 2017.

[3] Miljkovic, N., & Wang, E. N. MRS bulletin, 38(5), 397-406. 2013.

[4] Hoque, M. J., et al. Cell Reports Physical Science, 3(4), 2022.