Inspired by gecko's wonderful ability to stick to surfaces, NASA scientists have created a device that will adhere to almost anything.
The gecko is an extraordinary lizard. Out of the 5,600 species of lizard on the planet, over 1,500 belong to the gecko infraorder called Gekkota. Geckos have highly specialised toe pads.This enables them to climb vertical surfaces. They can even cross ceilings. Geckos can stick to walls and ceilings because of the attractive nature of intermolecular Van der Waals forces.
The 'gecko gripper' developed by NASA scientists uses very small silicon wedges to latch onto a wide range of slippery surfaces, like solar panels and plastics. NASA hopes to use gecko grippers in place of traditional adhesives like velcro, which are trickier to use in space and can leave behind residue. Since they’re made of silicon, the grippers can also withstand extreme pressure, temperature, and radiation conditions.
Gecko grippers adhere to testing objects using the same scientific forces as a gecko climbing up the glass in its tank. A single gecko foot contains about half a million tiny hairs called setae.The ends of these hairs may be small, but together they create a powerful connection between the foot and the surface. That connection takes advantage of Van der Waals forces, which occur when the electrons inside an atom or molecule aren’t evenly spaced, creating a negative pole and a positive pole. This causes other molecules or atoms nearby to become polarized, creating a weak electrical field that temporarily allows the gecko to stick. While gecko grippers use silicon wedges instead of setae, they too experience the sticky powers of Van der Waals forces.
Gecko grippers could be used for a variety of purposes, but scientists are especially interested in their ability to clean up floating debris in space. There are currently around 500,000 pieces of human-made debris hurtling around the planet, at speeds of up to 28164 km/h and experts predict that if the problem is not addressed soon it could prevent future launches. Chunks of space trash made up of defunct satellites, bits of spacecraft, and spent rockets already poses a threat to communications systems, space vehicles and astronauts.
