Scientist suggests super-sticky Spidey suit

A professor from the Polytechnic of Turin has developed a method for building a suit that could allow humans to cling to vertical surfaces like the comic book hero Spiderman.

The suit would use a similar principle used by geckos and spiders, which possess millions of tiny hairs on their limbs allowing them to stick to surfaces.

It is generally accepted that the microscopic hairs adhere to the surfaces, not by gripping in the traditional sense, but by using intermolecular phenomena called van der Waal forces, which are the same that allow an atom's protons not to burst apart.

Adhesion strength drops exponentially as the surface area and weight increases, so creating the same effect in a human-sized subject has been considered impossible.

However, Professor Nicola Pugno has calculated how sufficient stickiness could be generated in the same way to support an adult human's bodyweight.

This would be achieved by creating gloves and shoes coated in an hierarchical structure of carbon nanotubes to provide the same effect.

The grip of the gloves could be released with little effort by a peeling motion, which would break the adhesion little by little.

"Some researchers were able to measure an adhesion strength 200 times higher than that of a gecko. But there is a large gap between theory and practical applications," said Professor Pugno.

"If we are able to make a surface a little bit stronger, so that the size effect vanishes, we might be able to make a suit with the same adhesion as a gecko."

Professor Pugno predicted that we could see such suits by 2017, but added that they will need to be adhesive enough, easily detachable and self-cleaning if they are to be feasible.

"By using something like nanotubes we should be able to create sufficient attractive force to easily support a human, and by laying them out a hierarchical structure, the user should be able easily detach each limb in a simple peeling motion," he said.

The last requirement is slightly less obvious. The nature of the design means that tiny dirt particles could begin to clog up the nanotube fibres, gradually reducing the stickiness of the suit.

One method of counteracting this would be to make the suit hydrophobic, so that it strongly repels water. As water droplets are forced away from the contact areas of the outfit, they should wash away particles of dirt.

"To have all these mechanisms working together is difficult, because they are in competition with one another," Professor Pugno told the BBC News website. "But geckos and spiders provide a natural demonstration that this can be done."

Professor Pugno sees many useful applications for such a suit, ranging from window cleaning to space exploration.

The findings have been published in the Journal of Physics: Condensed Matter.