Strong Wet and Dry Adhesion by Cupped Microstructures
- Recent advances in bio-inspired microfibrillar adhesives have resulted in technologies that allow reliable attachment to a variety of surfaces. Because capillary and van der Waals forces are considerably weakened underwater, fibrillar adhesives are however far less effective in wet environments. Although various strategies have been proposed to achieve strong reversible underwater adhesion, strong adhesives that work both in air and underwater without additional surface treatments have yet to be developed. In this study, we report a novel design—cupped microstructures (CM)—that generates strong controllable adhesion in air and underwater. We measured the adhesive performance of cupped polyurethane microstructures with three different cup angles (15, 30, and 45°) and the same cup diameter of 100 μm in dry and wet conditions in comparison to standard mushroom-shaped microstructures (MSMs) of the same dimensions. In air, 15°CM performed comparably to the flat MSM of the same size with an adhesion strength (force per real contact area) of up to 1.3 MPa, but underwater, 15°CM achieved 20 times stronger adhesion than MSM ( ∼ 1 MPa versus ∼ 0.05 MPa). Furthermore, the cupped microstructures exhibit self-sealing properties, whereby stronger pulls lead to longer stable attachment and much higher adhesion through the formation of a better seal.
Document Type: | Article |
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Author: | Yue WangORCiD, Victor KangORCiD, Eduard ArztORCiD, Walter FederleORCiD, René HenselORCiD |
URN: | urn:nbn:de:bsz:291:415-4854 |
DOI: | https://doi.org/10.1021/acsami.9b07969 |
ISSN: | 1944-8244 |
Parent Title (English): | ACS Applied Materials & Interfaces |
Volume: | 11 |
Issue: | 29 |
First Page: | 26483 |
Last Page: | 26490 |
Language: | English |
Year of first Publication: | 2019 |
Release Date: | 2022/11/18 |
Tag: | cupped microstructures; polyurethane; self-healing; two-photon lithography; wet adhesion |
Impact: | 08.758 (2019) |
Funding Information: | European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 340929 and through the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement no 642861. |
Scientific Units: | Functional Microstructures |
Open Access: | Open Access |
Signature: | INM 2019/091 |
Licence (German): | Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International |