New gecko-inspired technology for climbing space robots

The grippers work on the same principle as gecko feet – by the bending of many tiny hair-like protrusions against a surface.

Conventional tapes that we use may seem magical (all hail Lord Ducttape), but they have flaws: the adhesive loses its tackiness after a few uses, rendering it virtually useless. Parness and his colleagues created a material studded with synthetic hairs, each of them much smaller than a human hair. Due to an even spacing of electrons around an atom, when together these form an electrical field. To get a tight grip on instruments, the grippers mimic the gecko, using thousands of electrically charged “follicles” to grasp onto a tool or nab an errant satellite, or simply keep something from floating away on the ISS (instead of using velcro.) It’s a technology that’s been in progress for years now, but this is a handy top-level look at how it works. These two sides attract each other, and result in a sticky effect that persists in different temperatures, pressures and under intense radiation, and can be reused endlessly.

NASA’s Jet Propulsion Laboratory has already successfully used its “gecko grippers” to stick a 100 kilogram person to a wall and manipulate a 10 kilogram cube during tests conducted in micro-gravity.

The newest generation of grippers can support more than 150 Newtons of force, the equivalent of 16 kilogrammes. The applications are numerous: in addition to anchors for astronauts (currently in development), the gecko-like material could also equip robots to crawl around the outside of the Space Station. It was found that despite being tested in severe conditions, the adhesive remained strong.

The anchors are made now in footprints of 1 by 4 inches, 2 by 6 inches and 3 by 8 inches.

They would serve as an experiment to test the gecko adhesives in microgravity for long periods of time and as a practical way for astronauts to attach clipboards, pictures and other handheld items to the interior walls of the station.

Parness and colleagues are collaborating with Nasa’s Johnson Space Centre in Houston on this concept.

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.

For testing, the robot manoeuvres across mock-up solar and radiator panels to emulate that environment.

This artist’s concept shows how a future robot called LEMUR (Limbed Excursion Mechanical Utility Robot) could inspect and maintain installations on the global Space Station.

The California Institute of Technology in Pasadena manages JPL for NASA.