PARIS, January 02, 22:02 /ITAR-TASS/. The European Space Agency (ESA) is creating a gecko robot for repairs in outer space, which will have six legs imitating the stickiness of the gecko lizard feet.
Scientists have built a 240-gram robot prototype named Abigaille. Its six legs are provided with microfibers that are much rougher than those of lizards whose feet are sticky due to little hairs with ends a thousand times thinner than a human hair. And yet this is enough to keep a small robot in place on various smooth man-made surfaces or allow it crawl from one such surface to another even at an angle of 90 degrees.
Michael Henrey of Simon Fraser University, who is the project manager, said “this approach is an example of ‘biomimicry’, taking engineering solutions from the natural world.”
“We’ve borrowed techniques from the microelectronics industry to make our own footpad terminators,” he said. “Technical limitations mean these are around 100 times larger than a gecko’s hairs, but they are sufficient to support our robot’s weight.”
“The reason we’re interested in dry adhesives is that other adhesive methods wouldn’t suit the space environment,” Henrey said. “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.”
“Velcro requires a mating surface, and broken hooks could contaminate the robot’s working environment. Magnets can’t stick to composites, for example, and magnetic fields might affect sensitive instruments,” he observed.
“A depth-sensing indentation instrument was used inside a vacuum chamber to precisely assess the dry adhesive’s sticking performance,” Laurent Pambaguian of ESA said, adding that “experimental success means deployment in space might one day be possible.”
“It’s very expensive to upgrade hardware once it is up in space so the idea would be to fly a more general robot in the first place,” Henrey said. “This could then be adapted through software upgrades for different tasks that weren’t anticipated at the start of the project.
“Our Abigaille climbing robot is therefore quite dexterous, with six legs each having four degrees of freedom, so it should be handle environments that a wheeled robot could not. 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,” the scientist said.