Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact
URL to paper listed on conference site
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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Nano Science and Technology Institute
2011
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| Online Access: | http://hdl.handle.net/1721.1/64767 https://orcid.org/0000-0002-6846-152X |
| _version_ | 1826208217421578240 |
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| author | Varanasi, Kripa K. Deng, Tao Hsu, Ming Bhate, Nitin |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Varanasi, Kripa K. Deng, Tao Hsu, Ming Bhate, Nitin |
| author_sort | Varanasi, Kripa K. |
| collection | MIT |
| description | URL to paper listed on conference site |
| first_indexed | 2024-09-23T14:02:02Z |
| format | Article |
| id | mit-1721.1/64767 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T14:02:02Z |
| publishDate | 2011 |
| publisher | Nano Science and Technology Institute |
| record_format | dspace |
| spelling | mit-1721.1/647672022-10-01T18:42:52Z Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact Varanasi, Kripa K. Deng, Tao Hsu, Ming Bhate, Nitin Massachusetts Institute of Technology. Department of Mechanical Engineering Varanasi, Kripa K. Varanasi, Kripa K. URL to paper listed on conference site In this paper, we present static and dynamic wetting interactions of water droplets on a variety of superhydrophobic surfaces. For sessile droplets, wetting states were determined by measuring contact angles and comparing them to that obtained from equilibrium Cassie and Wenzel states. Surprisingly, we find that roll-off angles are minimized on surfaces expected to induce Wenzel-like wetting in equilibrium. We argue that droplets on these surfaces are metastable Cassie droplets whose internal Laplace pressure is insufficient to overcome the capillary pressure resulting from the energy barrier required to completely wet the posts. In the case of impacting droplets the water hammer and Bernoulli pressures must be compared with the capillary pressure. Experiments with impacting droplets using a high-speed camera and specific surface textures that can delineate various wetting regimes show very good agreement with this simple pressurebalance model. These studies show that hierarchical micronano surfaces are optimum for droplet impact resistance. GE Global Research Center 2011-07-07T19:23:28Z 2011-07-07T19:23:28Z 2009-05 Article http://purl.org/eprint/type/ConferencePaper 9781439817858 http://hdl.handle.net/1721.1/64767 Varanasi, Kripa K. et al. "Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact." in Technical Proceedings of the 2009 NSTI Nanotechnology Conference and Expo, May 3-7, 2009, George R. Brown Convention Center, Houston, Texas, U.S.A. https://orcid.org/0000-0002-6846-152X en_US http://www.nsti.org/Nanotech2009/abs.html?i=761 Technical Proceedings of the 2009 NSTI Nanotechnology Conference and Expo, NSTI Nanotech 2009 Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Nano Science and Technology Institute MIT web domain |
| spellingShingle | Varanasi, Kripa K. Deng, Tao Hsu, Ming Bhate, Nitin Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact |
| title | Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact |
| title_full | Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact |
| title_fullStr | Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact |
| title_full_unstemmed | Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact |
| title_short | Hierarchical Superhydrophobic Surfaces Resist Water Droplet Impact |
| title_sort | hierarchical superhydrophobic surfaces resist water droplet impact |
| url | http://hdl.handle.net/1721.1/64767 https://orcid.org/0000-0002-6846-152X |
| work_keys_str_mv | AT varanasikripak hierarchicalsuperhydrophobicsurfacesresistwaterdropletimpact AT dengtao hierarchicalsuperhydrophobicsurfacesresistwaterdropletimpact AT hsuming hierarchicalsuperhydrophobicsurfacesresistwaterdropletimpact AT bhatenitin hierarchicalsuperhydrophobicsurfacesresistwaterdropletimpact |