Condensate droplet roaming on nanostructured superhydrophobic surfaces
Abstract Jumping of coalescing condensate droplets from superhydrophobic surfaces is an interesting phenomenon which yields marked heat transfer enhancement over the more explored gravity-driven droplet removal mode in surface condensation, a phase change process of central interest to applications...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-01-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-025-56562-x |
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| author | Cheuk Wing Edmond Lam Kartik Regulagadda Matteo Donati Abinash Tripathy Gopal Chandra Pal Chander Shekhar Sharma Athanasios Milionis Dimos Poulikakos |
| author_facet | Cheuk Wing Edmond Lam Kartik Regulagadda Matteo Donati Abinash Tripathy Gopal Chandra Pal Chander Shekhar Sharma Athanasios Milionis Dimos Poulikakos |
| author_sort | Cheuk Wing Edmond Lam |
| collection | DOAJ |
| description | Abstract Jumping of coalescing condensate droplets from superhydrophobic surfaces is an interesting phenomenon which yields marked heat transfer enhancement over the more explored gravity-driven droplet removal mode in surface condensation, a phase change process of central interest to applications ranging from energy to water harvesting. However, when condensate microdroplets coalesce, they can also spontaneously propel themselves omnidirectionally on the surface independent of gravity and grow by feeding from droplets they sweep along the way. Here we observe and explain the physics behind this phenomenon of roaming of coalescing condensate microdroplets on solely nanostructured superhydrophobic surfaces, where the microdroplets are orders of magnitude larger than the underlaying surface nanotexture. We quantify and show that it is the inherent asymmetries in droplet adhesion during condensation, arising from the stochastic nature of nucleation within the nanostructures, that generates the tangential momentum driving the roaming motion. Subsequent dewetting during this conversion initiates a vivid roaming and successive coalescence process, preventing condensate flooding of the surface, and enhancing surface renewal. Finally, we show that the more efficient conversion process of roaming from excess surface energy to kinetic energy results in significantly improved heat transfer efficiency over condensate droplet jumping, the mechanism currently understood as maximum. |
| format | Article |
| id | doaj-art-83b091463b244870bd8917bf069c53c3 |
| institution | Kabale University |
| issn | 2041-1723 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-83b091463b244870bd8917bf069c53c32025-02-02T12:33:03ZengNature PortfolioNature Communications2041-17232025-01-0116111110.1038/s41467-025-56562-xCondensate droplet roaming on nanostructured superhydrophobic surfacesCheuk Wing Edmond Lam0Kartik Regulagadda1Matteo Donati2Abinash Tripathy3Gopal Chandra Pal4Chander Shekhar Sharma5Athanasios Milionis6Dimos Poulikakos7Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH ZurichLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH ZurichLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH ZurichLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH ZurichThermofluidics Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology RoparThermofluidics Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology RoparLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH ZurichLaboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH ZurichAbstract Jumping of coalescing condensate droplets from superhydrophobic surfaces is an interesting phenomenon which yields marked heat transfer enhancement over the more explored gravity-driven droplet removal mode in surface condensation, a phase change process of central interest to applications ranging from energy to water harvesting. However, when condensate microdroplets coalesce, they can also spontaneously propel themselves omnidirectionally on the surface independent of gravity and grow by feeding from droplets they sweep along the way. Here we observe and explain the physics behind this phenomenon of roaming of coalescing condensate microdroplets on solely nanostructured superhydrophobic surfaces, where the microdroplets are orders of magnitude larger than the underlaying surface nanotexture. We quantify and show that it is the inherent asymmetries in droplet adhesion during condensation, arising from the stochastic nature of nucleation within the nanostructures, that generates the tangential momentum driving the roaming motion. Subsequent dewetting during this conversion initiates a vivid roaming and successive coalescence process, preventing condensate flooding of the surface, and enhancing surface renewal. Finally, we show that the more efficient conversion process of roaming from excess surface energy to kinetic energy results in significantly improved heat transfer efficiency over condensate droplet jumping, the mechanism currently understood as maximum.https://doi.org/10.1038/s41467-025-56562-x |
| spellingShingle | Cheuk Wing Edmond Lam Kartik Regulagadda Matteo Donati Abinash Tripathy Gopal Chandra Pal Chander Shekhar Sharma Athanasios Milionis Dimos Poulikakos Condensate droplet roaming on nanostructured superhydrophobic surfaces Nature Communications |
| title | Condensate droplet roaming on nanostructured superhydrophobic surfaces |
| title_full | Condensate droplet roaming on nanostructured superhydrophobic surfaces |
| title_fullStr | Condensate droplet roaming on nanostructured superhydrophobic surfaces |
| title_full_unstemmed | Condensate droplet roaming on nanostructured superhydrophobic surfaces |
| title_short | Condensate droplet roaming on nanostructured superhydrophobic surfaces |
| title_sort | condensate droplet roaming on nanostructured superhydrophobic surfaces |
| url | https://doi.org/10.1038/s41467-025-56562-x |
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