I love this new ecology of bio-mimiced robots.

From Wired UK:

The gecko’s toe hairs interact with the wall in a molecular attraction called “van der Waals force“. Using this force, a gecko can hang and support its whole weight on one toe. It only sticks when you pull in one direction.

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For this reason geckos have rotational ankles to ensure that they stick at whatever angle they are running. Their rear feet turn backwards when they are upside down or walking down a wall head first — otherwise they’d fall.

Such one-way adhesives are important for climbing because they require little effort to attach and detach a robot’s foot. Otherwise you have to press the foot down firmly to attach it and then work just as hard to pull the foot off. Directional adhesion is more like hooking and unhooking yourself from a surface.

With this in mind, Cutkosky and his team began asking how to build artificial materials that create the same effect. They came up with a rubber-like material with tiny polymer hairs made from micro-scale mould and attached it to a robot. The research was described in the journal Applied Physics Letters.

A layer of the adhesive was cut to cover a mechanical lizard’s foot. The newest versions of the adhesive have a two-layer system, similar to the gecko’s lamellae and setae, and allow Stickybot to climb smooth surfaces such as metal and glass. The scientists hope to develop the material to allow humans to climb walls like geckos, using technology called Z-Man.