A new transparent, bio-inspired coating makes ordinary glass tough, self-cleaning, and incredibly slippery. Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard School of Engineering and Applied Sciences, Boston, say that the new coating could be used to create new medical diagnostic devices, as well as durable, scratch-resistant lenses for eyeglasses, self-cleaning windows, and improved solar panels.

The scientists created the glass honeycomb-like structure with craters, coating it with a Teflon-like chemical that binds to the honeycomb cells to form a stable liquid film. The film repels droplets of both water and oily liquids. Slides treated this way withstood damage and remained slippery after various treatments that can scratch and compromise ordinary glass surfaces and other popular liquid-repellent materials, including touching, peeling off a piece of tape, and wiping with a tissue.

The new coating builds on an award-winning technology called Slippery Liquid-Infused Porous Surfaces (SLIPS), the most slippery synthetic surface known. The new coating is equally slippery, but more durable and fully transparent. Together these advances solve longstanding challenges in creating commercially useful materials that repel almost everything.

The team is now honing its method to better coat curved pieces of glass as well as clear plastics such as Plexiglas, and to adapt the method for the rigors of manufacturing.