Robotic pincers inspired by geckos could help collect garbage in space, a new study finds.
In experiments, the device was able to glom on to objects in the lab and even floating items within the International Space Station. Someday, such grippers could be used in maintenance robots in space or factory robots on Earth, according to the researchers, who reported the results of their study in the June 28 issue of the journal Science Robotics.
More than 500,000 pieces of debris currently orbit Earth, according to NASA. This space junk can travel at speeds of up to about 17,500 mph (28,100 km/h), posing a major hazard to astronauts, satellites and spacecraft. [Worst Space Debris Events of All Time]
Collisions with orbiting debris have already led to millions of dollars in losses. Moreover, such disasters can generate more debris that could go on to destroy more objects in space — a catastrophic chain-reaction scenario known as the "Kessler syndrome."
Despite the hazards that space junk poses, space debris is not collected today, in part because technologies used to grab on to items on Earth often do not perform well in space, the researchers said in their study. For instance:
* Conventional robotic hands are not suited for large, smooth pieces of space debris.
* Magnets do not stick to glass or aluminum.
* Suction cups require an atmosphere to work.
* Traditional sticky materials, such as tape, are largely useless because the chemicals they rely on cannot withstand the extreme temperature swings they would experience in space.
* Harpoons and nets could push objects in unintended directions.
Now, scientists have developed robotic pincers inspired by geckos to help grab space trash. The device was able to successfully snag floating objects in microgravity flights on both Earth and the International Space Station.
"We are really amazed at how much the gripper could achieve in floating environments," study lead author Hao Jiang, a mechanical engineer at Stanford University in California, told Space.com.
Geckos are reptiles that can scale vertical walls and even hang upside down by just their toes. The animals' plump toes are covered in hundreds of microscopic bristles that generate a kind of electric force strong enough to keep the lizards stuck onto surfaces. Scientists have developed many synthetic adhesives with gecko-like properties, enabling researchers to climb walls and seal wounds.
The new gripper is not as complex as a gecko's foot. Its adhesive uses flaps that are about 40 micrometers (millionths of a meter) wide, whereas geckos rely on structures that are about 200 nanometers (billionths of a meter) wide.