How Gecko-Inspired Robots Can Cling to Spaceships

The European Space Agency has shown that robots with gecko-like sticky feet could work just as well in space as here on Earth.

The family of “Abigaille” climbing robots has dry adhesive feet much like that of a wall-scaling lizard. They’re not sticky to touch like glue or tape, but adhere to smooth surfaces to let the robots hold tight while also remaining mobile.

It’s a neat example of robots once again borrowing tricks from nature. As the ESA explained on their site, gecko’s feet are covered in tiny hairs that help them cling to a vertical surface thanks to atomic interactions between the ends of the hairs and the wall. This is known as the Van der Waals force; the sum of various forces between molecules works to hold the gecko in place. The robots’ “foot hairs” are 100 times bigger than a gecko’s and made of microfibres, but they work in the same way.

The ESA tested the dry adhesive materials in space-like conditions at its Electrical Materials and Process Labs in the Netherlands, along with researchers from the Simon Fraser University in Canada, where the dream of gecko-style climbing 'bots first hatched back in 2011.

After finding that the same kind of sticking mechanism worked just fine in a vacuum and in space temperatures, they suggested the robots could one day be used to crawl around a spacecraft's hull and help tend to it. It would put a whole new spin on "space walk."

SFU engineer Michael Henrey explained that other sticky solutions wouldn’t work as well in crushing void of space. “Scotch, duct or pressure-sensitive tape would collect dust, reducing their stickiness over time. They would also give off fumes in vacuum conditions, which is a big no-no because it might affect delicate spacecraft systems,” he said. Velcro hooks could break off too easily, and magnets wouldn’t stick to all surfaces.

The Abigaille prototype looks more like a spider than a gecko, and Henrey said its six legs, each of which has four degrees of freedom, would make it a versatile tool in space: “For example, it can transition from the vertical to horizontal, which might be useful for going around a satellite or overcoming obstacles on the way,” Henry added.

It sounds like a more useful application of a space robot than tweeting, anyway.

@VickiTurk