Gecko Gloves Let Scientist Climb Sheer Glass Walls

Gecko foot
A gecko's foot seen on glass. Bjørn Christian Tørrissen

An American engineer has made a pair of gloves inspired by geckos' feet that could allow him to climb glass buildings, bringing super-hero fantasy closer to reality.

Mechanical engineer Elliot Hawkes of Stanford University developed the gloves, which are designed to support a person's weight, by mimicking the sticky pad of a gecko's feet.

Rather than sticking to the surface, the gloves use friction to hold the wearer in place by increasing the surface area of the gloves with hair-like nanofibers. Hawkes and his colleagues are the first to successfully develop a material that could function in this way.

Work on the gecko gloves began as a collaboration with Draper Labs in Cambridge, Massachusetts as part of the Z-Man project run by the Defence Advanced Research Projects Agency (DARPA). Hawkes tells Newsweek that "The Z-Man program was set up so that any human testing, and all interactions with the military, were performed by Draper", and most of this work is classified, according to Hawkes. "We and other university partners focused on advancing the underlying adhesive technology and manufacturing processes," he explains.

The gecko has been used as inspiration in past scientific exploration of the field. In 2011 Jeff Krahn, an engineer from Simon Fraser University in British Columbia, engineered a small robot that could hang from sheer glass using a similarly gecko-inspired mechanism. However, until now, engineering a material that could balance human weight posed a seemingly insurmountable challenge to researchers.

Species like the gecko are able to adhere to and climb vertical surfaces, but larger species are too heavy, meaning that even with the gecko's pads, the pull of gravity would outweigh the friction holding them to the wall.

To work around this, Hawkes and his colleagues developed a reptile-inspired dry-adhesive material called PDMS microwedges. Hair-like nanofibers cling and react to a surface, flattening out when pulled downward and gripping by electromagnetic attraction.

"To work," Hawkes says, "the surface you're climbing needs to be relatively smooth; like glass, varnished wood, polished stone, or metal." It takes very little effort to attach and detach from the surface, according to Hawkes, and to make the gloves stick, "all you have to do is hang your weight". The surface you're climbing on must also be dry.

They then used a material called 'shape-memory alloy' to attach these PDMS microwedges to patches, which are adhered to a flat plate. When held in the hand, the plate distributes human weight effectively enough to climb with. According to their calculations, Hawkes and his colleagues say the gloves can support up to 200 lbs.

Kellar Autumn, a biomechanical engineer at Lewis & Clark College who studies gecko adhesion but was not involved in the project told Popular Mechanics: "This is a really big deal. I've been dreaming about this for about 15 years, since we first discovered the mechanism that makes geckos stick to walls. And this is proof that we finally understood it well enough to make a person climb a building."

Hawkes explains to Newsweek that "The current version of the gloves is designed specifically for climbing glass, but this obviously doesn't have a huge market. So more realistic applications of the technology are using the devices to grasp and move large objects." The scientists are currently collaborating with NASA JPL - the leading US centre for robotic exploration in the solar system - for use of the gloves in space "to grasp 'space junk', dead satellites and such, that are in the way of live satellites, and move these debris into a 'graveyard orbit,' out of the way." The gloves can also be applied for "moving large glass objects, such as automotive windshields, TV screens, or solar panels in manufacturing," Hawkes says.

The gecko glove team has also been contacted by a venture capitalist who wants to make rock climbing gloves based on the glove's technology. "We are exploring options," Hawkes says, "since gripping rocks is a slightly different challenge than gripping glass."

The journey to make the gloves commercially available has also begun as Hawkes and his colleagues are working with Stanford to license the technology to other companies.