Pitcher plants make a living by drowning insects inside special cup-shaped leaves and then feeding on their remains. To get the insects to fall in and stay in, the plants have evolved an exceptionally slippery substance to coat their leaves, and a new synthetic material that mimics this substance is ten times slipperier than the next best thing.
Researchers at Harvard University have created a substance called SLIPS (slippery liquid-infused porous surfaces) that mimic the nanostructure of pitcher plant rims, and they've done such a good job that SLIPS is both more slippery than the natural pitcher plant material and also more slippery than any artificial material as well, including Teflon.
To make it work, the scientists covered a surface with a random network of tiny fibers, each a thousand times thinner than a human hair. This tangle of fibers acts sort of like a sponge, and when you squirt some lubricant in there, the fibers grab onto it, forming what is essentially a surface of pure lubricant, held together by the underlying sponge structure. Water runs right off this surface without leaving a stain, as does paint, blood, oil, jam, and of course it's impervious to insects. The surface is so smooth, in fact, that ice can't form on it, since as soon as an ice crystal forms, it slides right off. The figure below shows a strip of Teflon between two pieces of SLIPS, and illustrates how much Teflon sucks compared to this stuff:
The best news about SLIPS is that unlike most other materials this cool, it's easy to make. The underlying nanostructure can be created out of widely available materials using a simple process, and any number of different liquid lubricants can be used. Since there's a liquid trapped in the surface, SLIPS are self-cleaning and self-heal from any damage within seconds, they work under a wide variety of temperatures and pressures, and they can be made to be completely transparent.
So what can we do with SLIPS? Anything you want! How about a coating for your car that means you'll never have to wash it ever again, or touchscreens that never get smudged, or the world's slipperiestslip 'n slide (wheeee!). It's gonna take a little bit for this stuff to make its way out of the lab, of course, but it's such awesome stuff that it'll hopefully be out of there faster than a greased pig. A greased pig greased with SLIPS, that is.
Nature, via Discover
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