NASA engineers say they've turned to nature – and to the super-sticky feet of geckos – to design robots that may some day climb around the outside of the International Space Station.
Using a "gecko gripper" system, such robots could conduct inspections and repairs to the exterior of the ISS, and also possibly conduct scientific research, say researchers at the space agency's Jet Propulsion Laboratory in Pasadena, Calif.
Gecko feet are extremely sticky, but not in the way adhesives or glues are, the engineers explain.
Instead, the gecko's feet have millions of tiny hair-like spikes that let them cling to walls and even ceilings, thanks to a phenomenon known as van der Waals forces.
Molecules – whether in the wall or the gecko's feet – have positive and negative sides, so the side of one molecule will attract the oppositely charged side of a neighboring molecule.
Multiply that by the millions or even billions of molecules involved, and you get the "stickiness" that allows geckos to climb walls and cling to ceilings.
To explain the technology behind the concept, NASA has released a YouTube video.
JPL researchers have mimicked that gecko stickiness, developing a material studded with millions of tiny synthetic fibers that provide adhesion in the same manner as the protrusions on a gecko's feet.
That's allowed them to created grippers that can support as much as 35 pounds, they say.
A robot with such grippers could easily mover around on the surface of the space station, they suggest.
"The grippers don't leave any residue and don't require a mating surface on the wall the way Velcro would," says engineer Aaron Parness.
The gecko system is superior because it doesn't lose its stickiness over time the way tape or even Velcro would, the researchers say, and it works in environments of extreme pressures, temperatures or radiation.
The JPL engineers say they're also looking at using the gecko system to create anchors for astronauts that would help them inside the International Space Station, allowing them to quickly and easily attach clipboards, pictures and other handheld items to the interior walls of the ISS.
The technology could eventually find uses beyond the space station, Parness says.
"We might eventually grab satellites to repair them, service them, and we also could grab space garbage and try to clear it out of the way," he suggests.
