Sorting of droplets by migration on structured surfaces
Background: Controlled transport of microdroplets is a topic of interest for various applications. It is well known that liquid droplets move towards areas of minimum contact angle if placed on a flat solid surface exhibiting a gradient of contact angle. This effect can be utilised for droplet manip...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Beilstein-Institut
2011-04-01
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| Series: | Beilstein Journal of Nanotechnology |
| Subjects: | |
| Online Access: | https://doi.org/10.3762/bjnano.2.25 |
| _version_ | 1818511032784519168 |
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| author | Wilfried Konrad Anita Roth-Nebelsick |
| author_facet | Wilfried Konrad Anita Roth-Nebelsick |
| author_sort | Wilfried Konrad |
| collection | DOAJ |
| description | Background: Controlled transport of microdroplets is a topic of interest for various applications. It is well known that liquid droplets move towards areas of minimum contact angle if placed on a flat solid surface exhibiting a gradient of contact angle. This effect can be utilised for droplet manipulation. In this contribution we describe how controlled droplet movement can be achieved by a surface pattern consisting of cones and funnels whose length scales are comparable to the droplet diameter.Results: The surface energy of a droplet attached to a cone in a symmetry-preserving way can be smaller than the surface energy of a freely floating droplet. If the value of the contact angle is fixed and lies within a certain interval, then droplets sitting initially on a cone can gain energy by moving to adjacent cones.Conclusion: Surfaces covered with cone-shaped protrusions or cavities may be devised for constructing “band-conveyors” for droplets. In our approach, it is essentially the surface structure which is varied, not the contact angle. It may be speculated that suitably patterned surfaces are also utilised in biological surfaces where a large variety of ornamentations and surface structuring are often observed. |
| first_indexed | 2024-12-10T23:28:01Z |
| format | Article |
| id | doaj.art-61035af319a842139843569e5d550072 |
| institution | Directory Open Access Journal |
| issn | 2190-4286 |
| language | English |
| last_indexed | 2024-12-10T23:28:01Z |
| publishDate | 2011-04-01 |
| publisher | Beilstein-Institut |
| record_format | Article |
| series | Beilstein Journal of Nanotechnology |
| spelling | doaj.art-61035af319a842139843569e5d5500722022-12-22T01:29:30ZengBeilstein-InstitutBeilstein Journal of Nanotechnology2190-42862011-04-012121522110.3762/bjnano.2.252190-4286-2-25Sorting of droplets by migration on structured surfacesWilfried Konrad0Anita Roth-Nebelsick1University of Tübingen, Institute for Geosciences, Sigwartstrasse 10, D-72076 Tübingen, GermanyState Museum of Natural History Stuttgart, Rosenstein 1, D-70191 Stuttgart, GermanyBackground: Controlled transport of microdroplets is a topic of interest for various applications. It is well known that liquid droplets move towards areas of minimum contact angle if placed on a flat solid surface exhibiting a gradient of contact angle. This effect can be utilised for droplet manipulation. In this contribution we describe how controlled droplet movement can be achieved by a surface pattern consisting of cones and funnels whose length scales are comparable to the droplet diameter.Results: The surface energy of a droplet attached to a cone in a symmetry-preserving way can be smaller than the surface energy of a freely floating droplet. If the value of the contact angle is fixed and lies within a certain interval, then droplets sitting initially on a cone can gain energy by moving to adjacent cones.Conclusion: Surfaces covered with cone-shaped protrusions or cavities may be devised for constructing “band-conveyors” for droplets. In our approach, it is essentially the surface structure which is varied, not the contact angle. It may be speculated that suitably patterned surfaces are also utilised in biological surfaces where a large variety of ornamentations and surface structuring are often observed.https://doi.org/10.3762/bjnano.2.25microdropletsmicrofluidicssurfacesurface energysurface structures |
| spellingShingle | Wilfried Konrad Anita Roth-Nebelsick Sorting of droplets by migration on structured surfaces Beilstein Journal of Nanotechnology microdroplets microfluidics surface surface energy surface structures |
| title | Sorting of droplets by migration on structured surfaces |
| title_full | Sorting of droplets by migration on structured surfaces |
| title_fullStr | Sorting of droplets by migration on structured surfaces |
| title_full_unstemmed | Sorting of droplets by migration on structured surfaces |
| title_short | Sorting of droplets by migration on structured surfaces |
| title_sort | sorting of droplets by migration on structured surfaces |
| topic | microdroplets microfluidics surface surface energy surface structures |
| url | https://doi.org/10.3762/bjnano.2.25 |
| work_keys_str_mv | AT wilfriedkonrad sortingofdropletsbymigrationonstructuredsurfaces AT anitarothnebelsick sortingofdropletsbymigrationonstructuredsurfaces |