Climb walls like spiderman!

Prototype "Spiderman gloves" that will enable window cleaners to scale walls, robots to scurry across ceilings and rock climbers to hang about could be ready within three years.

There has been popular interest in how to mimic his extraordinary wall climbing ability since 1962, when the web-slinging hero with superhuman strength was born in the pages of Marvel Comics.

Shy, nerdy Peter Parker managed the feat after being bitten by a radioactive spider on a science class field trip. Now there is no need to be of an arachnid persuasion but simply make like the gecko instead, given the lizard's uncanny ability to run up walls and across ceilings on its five toed feet.

A Californian team reports today that has got the hang of gecko adhesion and solved the mystery of how the lizards manage to stick without getting stuck, marking a boon for real life Peter Parkers.

"I think gecko-gloves for Spiderman type climbing could be made in three to five years," Prof Ron Fearing of the University of California, Berkeley, tells The Daily Telegraph.

While conventional adhesive tape sticks when pressed on a surface, the new gecko-inspired adhesive only adheres when it slides.

That is, it is a directional adhesive, exploiting the same effect which allows a real gecko to run up walls while rapidly attaching and detaching its toes, according to two studies published today in the journal Interface by Bryan Schubert, Jongho Lee and Prof Fearing.

Their gravity-defying power lies in the tens to hundreds of thousands of hair-like structures, known as setae, on geckos' toe pads.

Each foot is packed with about half a million setae. The tip of each hair has hundreds or thousands of projections, called spatulae, which measure about 10 millionths of an inch across and can get so close to a surface that weak "sticky" interactions between molecules in the pad and on the surface become significant.

The gecko-inspired smart adhesive, which is dry, uses hard plastic microscopic fibres of polypropylene that mimic this effect.

Each fibre is 15-20 micrometres (millionths of a metre) long, and 0.6 micrometres in diameter and has to be slid parallel to the surface to bend and thus attach.

As for the prospect of spidey gloves, "of course, climbing would require a good athlete, and it would probably be a good idea to have some extra contact area such as pads on knees, chest, and so on," says Prof Fearing.

"There are issues remaining to be solved, as in sticking to dirty or rough surfaces, such as you would find on the outside of a building.

The patch backing would need to be stronger as well, as high adhesion can deform the thin plastic backing.

If our current gecko tape were scaled up in area, an 11-stone (70 kg) climber would need a patch about four by four inches (10 by 10 cm) in area, but this would not leave much safety margin (geckos have safety factors of 10 to 100)."

While the present version works on smooth glass, future versions could be useful for medical equipment, sporting goods, or climbing robots where a controllable and reusable adhesive is needed. Gecko tape could have applications in space, where most adhesives do not work because of the vacuum.

"Gecko tape was proved as a concept a few years ago by our group," comments Prof Andre Geim of the University of Manchester.

"Since then, there have been several steps in the right direction to reach its commercial availability and the current papers are yet another one. But it requires a giant leap to make gecko tape available in shops, which we all are looking forward to."