New coating creates super slippery glass.
A new transparent, bioinspired coating makes ordinary glass tough, self-cleaning and incredibly slippery, according to a Harvard University team.
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.
SLIPS (Slippery Liquid-Infused Porous Surfaces) 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 like honey, and it resists ice formation and bacterial biofilms as well.
To create a SLIPS-like coating, the researchers corral a collection of tiny spherical particles of polystyrene, the main ingredient of Styrofoam, on a flat glass surface like a collection of Ping-Pong balls. They pour liquid glass on them until the balls are more than half buried in glass. After the glass solidifies, they burn away the beads, leaving a network of craters that resembles a honeycomb. They then coat that honeycomb with the same liquid lubricant used in SLIPS to create a tough but slippery coating.
By adjusting the width of the honeycomb cells to make them much smaller in diameter than the wavelength of visible light, the researchers kept the coating from reflecting light. This made a glass slide with the coating completely transparent.