This gecko-inspired robot could get a grip on space junk

Contributed by
Jul 7, 2017

NASA has harnessed the power of many things in nature: solar energy, gravitational lensing, radiation, isotopes and now gecko feet.

The lizard that you might recognize from ads that could save you that much more is now going beyond selling discount car insurance. Geckoes seem to almost defy gravity the way they stick to the surfaces they climb vertically and even hang upside down from. The secret is in their almost alien toes, whose hundreds of micro-bristles generate a sort of electric force that could inspire a million superheroes who want to cling to ceilings and scale skyscrapers. These super-feet have already influenced adhesives that almost magically seal wounds and a prototype of climbing gear that may someday spawn a real Spider-Man.  

Now NASA scientists are trying to emulate the gecko’s superpowers with a pair of robotic pincers that grab space junk before it can smash into spacecraft or satellites. Collisions with debris hurtling through space at up to 17,500 mph can threaten the lives of astronauts and potentially result in equipment damage that could cause the space agency to bleed millions of dollars, and destroy even more objects out there. Hazards of junk in space haven’t had much attention up until now because of the lack of successful technology. Magnets are powerless when faced with aluminum or glass, there actually needs to be an atmosphere around for suction cups to work, and most robotic hands can’t hold on to chunks of space debris for long. That is all about to change.

The underside of the artificial gecko foot, gripping a piece of glass in violet lighting.


While gecko feet get their grip from nano-structures 200 billionths of a meter wide, the new contraption is equipped with micro-flaps about 40 millionths of a meter wide, arranged in a grid of squares on the front and in narrow strips on each arm. The results were still astounding. In a feat that showed just how much strength is in those reptilian toes, the gripper was able to clamp on to objects floating in microgravity environments in the International Space Station and right here on Earth. Activating the grip takes almost zero force in zero gravity, where what we’d consider an insignificant tap on land is enough to send something flying. Just a slight push in the right direction is enough to snap up anything from solar panels to entire rocket bodies.

"We are really amazed at how much the gripper could achieve in floating environments," said team lead and mechanical engineer Hao Jiang of Stanford University. "The objects were really easy to knock away, so we are really happy that our adhesive gripper could grasp them with very little pressing force."

Almost as amazing is that this thing can handle debris up to 880 pounds and gets its intelligence from sensors that can monitor alignment and contact. Scientists see a future where the device is often part of a space robot’s anatomy. Some robots equipped with grippers would be charged with space cleanup, some with space construction, and others now able to crawl on smooth surfaces would oversee maintenance of satellites, space telescopes, the ISS and deep space missions.


Being a human anti-gravity lizard.


The prototype itself hasn’t yet taken off. It still needs to be tested outside in extreme temperatures and killer radiation, and the grippers will eventually have tactile sensors that detect adhesion in real time. But we’re close. Jiang is confident that the technology will soon be viable to use in outer space, and geckoes everywhere are flattered.