Scientists at the space agency’s Jet Propulsion Laboratory (JPL) in Pasadena, California, are developing a “gecko gripper” system that could help robots inspect and fix the space station’s exterior, and perhaps conduct a wide range of activities in Earth orbit.
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“This is how the gecko does it, by weighting its feet,” said NASA engineer Aaron Parness. All this thanks to the gecko-inspired technology, which permits the grippers to seize those objects, via thousands of electrically-charged “follicles”.
It seems that the prototype robot was able to handle and stick to a 10 kg cube, and a person weighing 100 kg.
The lizards can turn this adhesive force on by pushing their feet down and bending the tiny “hairs”, Parness said.
As a related NASA statement explains, “A slight electrical field is created because electrons orbiting the nuclei of atoms are not evenly spaced, so there are positive and negative sides to a neutral molecule”. The gripping surface does not lose its stickiness or wear out quickly like other forms of tapes and adhesives.
It is remarkable how the sticky effect lasts and can be reused endlessly, while it persists at pressures and different temperatures.
To develop the next generation of exploratory space robots, the US space agency has turned to geckos for “ultimate stickiness”.
“The grippers don’t leave any residue and don’t require a mating surface on the wall the way Velcro would”, Parness said.
The latest generation of grippers can support more than 150 Newtons of force, which is the equivalent of 35 lbs. Just as a gecko’s foot has tiny adhesive hairs, the JPL devices have small structures that work in similar ways. More than 30,000 stick-and-unstick repetitions have shown no loss of effectiveness, and the hope is the new material could soon be used on the worldwide Space Station. The anchors are made now in footprints of 1 by 4 inches, 2 by 6 inches and 3 by 8 inches.
Nasa is also working on a Lemur 3 climbing robot which would use the gecko-inspired technology to climb on the outside of spacecraft, performing inspections with more deftness than robotic arms or rocket-powered cameras. This part of the project is a collaboration between JPL and the Johnson Space Center.
The gecko grippers could one day be used to mount objects on the inside of the worldwide Space Station.
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For testing, the robot maneuvers across mock-up solar and radiator panels to emulate that environment.
