Researchers at Harvard University, Cambridge, Mass., have developed a transparent, bioinspired coating that makes ordinary glass tough, self-cleaning, and extremely slippery. Researchers produce the ultraslippery coating by building a glass honeycomb-like structure with craters (left in the diagram), coating it with a Teflon-like chemical (purple) that binds to the honeycomb cells to form a stable liquid film. That film repels droplets of both water and oily liquids (right). Because it’s a liquid, it flows, which helps the coating repair itself when damaged.
The new coating could be used to create durable, scratch-resistant lenses for eyeglasses, self-cleaning windows, improved solar panels, and new medical diagnostic devices, said principal investigator Professor Joanna Aizenberg, Ph.D. The new coating builds on an award-winning technology that Prof. Aizenberg and her team pioneered called Slippery Liquid-Infused Porous Surfaces (SLIPS) — the slipperiest synthetic surface known.
The new coating is equally slippery, but much more durable and fully transparent. Together these advances solve longstanding challenges in creating commercially useful materials that repel almost everything. SLIPS was inspired by the slick strategy of the carnivorous pitcher plant, which lures insects onto the ultraslippery surface of its leaves, where they slide to their doom. Unlike earlier water-repelling materials, SLIPS repels oil and sticky liquids such as honey, and it resists ice formation and bacterial biofilms as well.
The advance was made by a team from the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard School of Engineering and Applied Sciences (SEAS) reported online in the July 31 edition of Nature Communications (“Transparency and damage tolerance of patternable omniphobic lubricated surfaces based on inverse colloidal monolayers”).
