Electric pump can switch strong adhesion on and off

Published On Tue Feb 2 2010, Lesley Ciarula Taylor Staff Reporter

Borrowing a defence that a South Florida beetle uses to fend off attacking ants, a group of biomolecular engineers has invented a device that could someday help people walk on walls.

The beetle uses the surface tension of water to stick to a palm leaf with “startling strength” that is 100 times its own weight, Dr. Paul Steen, professor of chemical and biomolecular engineering at Cornell University, told the Star. After eight years of research, Steen and his team have translated the beetle’s might into an electrical switch that can turn that surface tension off and off.

“Think of putting a little spittle on your finger and then rubbing your fingers,” Steen said. “You can feel a little tug. Then create a million of these.”

Their research is published in the current issue of Proceedings of the National Academy of Sciences.

In tests, a palm-sized plate punctured with hundreds of micron-sized conical holes could hold the weight of a Hershey bar or a Lego man until the little electrical pump was turned off; the plate dropped from the surface it was stuck to. (A micron is one-millionth of a metre).

The smaller the plate they created, the stronger the adhesion, said Steen. Researchers figure the same principles will lead them to create holes that are a tenth of a micron in size that could hold 15 pounds per square inch.

For full article, follow this link http://www.thestar.com/sciencetech/science/article/759324--scientists-invent-spider-man-device.