Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity
Wetting functionalities of rough surfaces are largely determined by the Laplace pressure generated across liquid–gas interfaces formed within surface structures. Typically, rough wetting surfaces create negative Laplace pressures, enabling capillary wicking, while rough non‐wetting surfaces create p...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2024
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| Online Access: | https://hdl.handle.net/1721.1/154947 |
| _version_ | 1824457917499179008 |
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| author | Wilke, Kyle L Song, Youngsup Lu, Zhengmao Wang, Evelyn N |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Wilke, Kyle L Song, Youngsup Lu, Zhengmao Wang, Evelyn N |
| author_sort | Wilke, Kyle L |
| collection | MIT |
| description | Wetting functionalities of rough surfaces are largely determined by the Laplace pressure generated across liquid–gas interfaces formed within surface structures. Typically, rough wetting surfaces create negative Laplace pressures, enabling capillary wicking, while rough non‐wetting surfaces create positive Laplace pressures, exhibiting fluid repellency. Here, with microfabricated reentrant structures, it is shown that the same surface can exhibit either a negative or positive Laplace pressure, regardless of its intrinsic wettability. This material‐independent Laplace pressure duality enables or enhances a range of wetting functionalities including wicking, switchability, and selectivity. On the same surface, capillary rise, capillary dip, and the combination of the two which leads to further enhancement of the total sustainable capillary height and Laplace pressure, the driving force for wicking is demonstrated. Further, active switching of wetting states between the hemiwicking and the repellent Cassie state on reentrant structures is shown. Moreover, with a water‐hexane mixture system, selective wetting of reentrant structures are demonstrated, that is, water can be selectively wicked or repelled in the presence of hexane, and vice versa. These functionalities are achieved, which would typically require complex chemical coatings, solely using surface structures, thus largely expanding the design space for a wide range of thermofluidic applications. |
| first_indexed | 2024-09-23T08:58:35Z |
| format | Article |
| id | mit-1721.1/154947 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2025-02-19T04:17:37Z |
| publishDate | 2024 |
| publisher | Wiley |
| record_format | dspace |
| spelling | mit-1721.1/1549472024-12-23T05:56:49Z Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity Wilke, Kyle L Song, Youngsup Lu, Zhengmao Wang, Evelyn N Massachusetts Institute of Technology. Department of Mechanical Engineering Wetting functionalities of rough surfaces are largely determined by the Laplace pressure generated across liquid–gas interfaces formed within surface structures. Typically, rough wetting surfaces create negative Laplace pressures, enabling capillary wicking, while rough non‐wetting surfaces create positive Laplace pressures, exhibiting fluid repellency. Here, with microfabricated reentrant structures, it is shown that the same surface can exhibit either a negative or positive Laplace pressure, regardless of its intrinsic wettability. This material‐independent Laplace pressure duality enables or enhances a range of wetting functionalities including wicking, switchability, and selectivity. On the same surface, capillary rise, capillary dip, and the combination of the two which leads to further enhancement of the total sustainable capillary height and Laplace pressure, the driving force for wicking is demonstrated. Further, active switching of wetting states between the hemiwicking and the repellent Cassie state on reentrant structures is shown. Moreover, with a water‐hexane mixture system, selective wetting of reentrant structures are demonstrated, that is, water can be selectively wicked or repelled in the presence of hexane, and vice versa. These functionalities are achieved, which would typically require complex chemical coatings, solely using surface structures, thus largely expanding the design space for a wide range of thermofluidic applications. 2024-05-14T17:06:54Z 2024-05-14T17:06:54Z 2023-02 2024-05-14T17:00:25Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/154947 Wilke, Kyle L, Song, Youngsup, Lu, Zhengmao and Wang, Evelyn N. 2023. "Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity." Advanced Materials Interfaces, 10 (4). en 10.1002/admi.202201967 Advanced Materials Interfaces Creative Commons Attribution http://creativecommons.org/licenses/by/4.0/ application/pdf Wiley Wiley |
| spellingShingle | Wilke, Kyle L Song, Youngsup Lu, Zhengmao Wang, Evelyn N Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity |
| title | Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity |
| title_full | Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity |
| title_fullStr | Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity |
| title_full_unstemmed | Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity |
| title_short | Enhanced Laplace Pressures for Functional Surfaces: Wicking, Switchability, and Selectivity |
| title_sort | enhanced laplace pressures for functional surfaces wicking switchability and selectivity |
| url | https://hdl.handle.net/1721.1/154947 |
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