Self-cleaning Glass?

Ohio State University engineers are designing super-slick, water-repellent surfaces that mimic the texture of leaves on the water lily.

The technology could lead to self-cleaning glass, the researchers say, and it could also reduce friction between the tiny moving parts inside tiny devices.

Above is a scanning electron micrograph image of the surface of a water lily leaf, also called a lotus leaf. Scientists have long known the leaf is a good model for a water-repellent surface. The leaf is waxy and covered with tiny bumps, so water rolls off.

In studying the lotus leaf, researchers realized that the same texture could be exploited to reduce friction between moving parts on machines. Small machines, such as those under development in the fields of micro- and nanotechnology, can't be lubricated by normal means.

"In general, what's good for water-repellency is good for fighting friction," said the university's Bharat Bhushan.

Just copying a lotus leaf isn't enough. Bumpy, waxy surfaces can actually become sticky under some circumstances. So Bhushan and his colleagues have built the first computer model that calculates the best bumpy surface for different materials and applications.

The idea is that dirt would slide off a window, but you wouldn't see the teensy bumps.

-- LiveScience Staff

Image credit: Ohio State University