Researchers at UC Berkeley and Lewis and Clark College in Portland, Oregon created a sticky tape with technology that was stolen straight from the gecko. The new method of adhesion has unique properties that should find use in the medical device industry.
From the statement by the National Science Foundation:
Unlike duct tape or glue, the new material is crafted from millions of tiny, hard, plastic fibers that establish grip; a mere square two centimeters on a side can support 400 grams (close to a pound). While tape sticks when it presses onto a surface, the new adhesive sticks as it slides on a surface and releases as it lifts — this is the trick behind a gecko’s speedy vertical escapes.
The new study appeared online Jan. 23, 2008, in the Journal of the Royal Society Interface.
There are other synthetic adhesives inspired by gecko feet and they adhere much like conventional tape. In contrast, the new adhesive brushes along a surface to develop traction. While ideal for hanging posters, the characteristic is even more important for any application that requires movement, such as climbing.
“The gecko has a very sophisticated hierarchical structure of compliant toes, microfibers, nanofibers and nanoattachment plates that allows the foot to attach and release with very little effort,” said co-author and Berkeley professor Ron Fearing, “The gecko makes it look simple, but the animal needs to control the directions it is moving its toes–correct movement equates to little effort,” he said.
The new material is also novel in that it gets stronger with use. In experiments, it tightened its hold as it was rubbed repeatedly against a glass plate. The extra strength is caused by the fibers bending over to make more contact, yet once released, the fibers returned to their original shape. The research team is exploring ways to permanently bend the fibers so that the grip strength is its strongest from the outset, no massaging required.
According to Fearing, the new material is the first to mimic the nature of the gecko’s characteristic “non-sticky by default” feet.