A new device that can let humans walk on walls

The new technology could lead to development of shoes and gloves which would stick to vertical surfaces. The owner of such device would possess the abilities of Spider Man from the famous motion picture.
A device capable of building adhesive bonds with various objects was developed by Paul Steen and Michael Foghel from Cornell University, USA. The adhesive properties of the device are based on the surface tension of water. A palm-sized device consists of two plates and a porous layer between them. The bottom plate holds a liquid reservoir and the top plate is patterned with holes, each several hundred microns in diameter.

Electric field applied by a common 9-volt battery pumps water through the device and causes tiny droplets to squeeze through the top layer. The surface tension of the droplets allows the top plate to grip an object several times heavier than the device itself. The same physical principle makes two wet glass slides stick together.


The prototype designed at Cornell University can hold about 30 grams. Its top plate was made with about 1000 300-micron-sized holes. The weight that can be held by the device is in direct proportion to the number of holes and inverse to their size. 6.5-square-centimeter device with millions of 1-micron-sized holes could hold more than 7 kilograms.


To turn the adhesion off, the electric field is simply reversed.  

Source: Nature News