A couple of years ago, we first heard about a gecko-inspired reusable adhesive known as Geckskin. According to its creators at the University of Massachusetts Amherst, it could be used to hang objects weighing up to 700 pounds (318 kg) on smooth surfaces such as glass. Now, however, they've announced a new version that also works on rough surfaces, like drywall and wood.
Like the original Geckskin, this version differs from other gecko-inspired adhesives, in that it does not replicate the microscopic hair-like setae that are found on the underside of the lizards' feet.
As it turns out, while setae are one part of what allows geckos to maintain and release adhesion on a molecular level, they're not something that needs to be copied in order for Geckskin to work.
Instead, the material mimics the relationship between the animals' skin, bones and tendons. It does so by combining a base layer of very stiff material such as carbon fiber with a gripping layer of soft elastomer. In a process known as "draping adhesion," the elastomer conforms to the nooks and crannies of uneven surfaces, while the stiffer material provides tension, keeping the elastomer from letting go until the material is pulled in the right direction.
The scientists realized that by tweaking the stiffness of the rigid base material, it's possible to maximize adhesion for a variety of different surfaces – hence the new version of Geckskin. When compared to the gripping ability of a Tokay gecko, the adhesive matched or beat the lizard on all tested surfaces.
A paper on the research was recently published in the journal Advanced Materials. The new Geckskin can be seen in use in the video below.