Bioinspired Self-Repairing Slippery Surfaces with Pressure-Stable Omniphobicity
Entry by Emily Redston, AP 226, Spring 2012
- Work in progress*
Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity by T.S. Wong, S.H. Kang, S.K.Y. Tang, E.J. Smythe, B.D. Hatton, A. Grinthal, and J. Aizenberg. Nature 477, 443-447 (2011)
Researchers have classically drawn inspiration from the lotus effect when designing synthetic liquid-repellent surfaces. However, this approach has several inherent limitations, restricting its applicability. For instance, this method does not work well with organic liquids or complex mixtures with low surface tensions. Therefore, in this paper, the authors propose an alternative approach that derives from systems like the Nepenthes pitcher plant. Instead of using the structures to repel impinging liquids directly, these systems use them to lock-in an intermediary liquid that then acts by itself as the repellent surface.
Some Neat Videos
Movie 1 -- This movie demonstrates the fast recovery of the liquid-repellent function of a SLIPS after critical physical damage. As seen from the movie, the crude oil droplet is pinned on a nanostructured superhydrophobic surface (without lubricating fluid), while the droplet maintains its mobility on the SLIPS. Extra-light crude oil (from Appalachian Basin, USA) was used as the test liquid for demonstration.
Movie 2 -- This movie demonstrates the excellent ice-repellency of a SLIPS, as compared to a nanostructured surface. As seen from the movie, an ice block (formed from a frozen water droplet of ˜100 µL at –4 °C and ˜45% relative humidity) slides on the SLIPS under the influence of gravity. In comparison, an ice block of the same volume remains strongly pinned on a superhydrophobic nanostructured surface without a lubricating layer. This movie corresponds to Fig. 4c in the main text.
Movie 3 -- This movie demonstrates the self-cleaning ability of a SLIPS. As seen from the movie, carbon dust is seeded onto the SLIPS and can be easily removed by sliding an ethanol droplet across the surface. This movie corresponds to Fig. S7a in the Supplementary Information.