LC Professor aides breakthroughs in gecko research

Humans sticking to walls has always been thought of as a mere fantasy, associated with creatures of the arachnid variety. However, the recent development of a tape-like adhesive mimics the “sticking” process of the gecko, making Spiderman-like capabilities a distant, yet possible, reality.

It is not the first instance of synthetic adhesives inspired by geckos to be made, yet engineers from the University of California at Berkeley believe that they have created the closest man-made material yet to replicate the process that allows the lizard to stick and release to vertical surfaces with ease.  Ron Fearing, head of the research team and professor of electrical engineering and computer sciences at Berkeley, explains that past research has focused on the strength of the adhesion, whereas now ease of attachment and detachment play an equally important role in developing a gravity-defying adhesive.

The discovery stemmed from years of research by scientists across the country, including Fearing and Lewis & Clark Associate Professor of Biology, Kellar Autumn, one of the nation’s leading experts in the field of gecko adhesion. Their first findings came in 2000 when they discovered that the mysteries of gecko adhesion stemmed from intermolecular, or van der Waal’s, forces that are weak until surfaces get close to one another.  They learned that geckos have millions of tiny hairs that further split into billions of tips at the microscopic level. These split ends maximize the attraction of the intermolecular forces, allowing the gecko hairs to stick to the surface when they make contact.

Autumn, who was not directly involved with this latest research, is enthusiastic about what lies ahead. “This is an exciting milestone in the new field of gecko-inspired  adhesives,” he said. “Fearing’s adhesive is made from a plastic that is very hard, like real gecko protein, so it is not ‘sticky’ to the touch.” The new material is made from millions of tiny, stiff plastic fibers. A two-centimeter square has the strength to support four hundred grams or nearly a pound. While it is considered an adhesive like tape or glue, it is different in how it is stuck to a surface. Conventional adhesives bond when pressed on to a surface, whereas the gecko-inspired adhesive slides onto a surface and releases when it lifts, much like how a lizard ascends walls.

As amazing as the breakthrough is, it is still limited. The material can hold, at most, a few pounds at a time, and it only works on smooth surfaces such as glass, which must be clean and free of dust.  Looking to the future, Fearing and his team are working to develop material that can adhere to rough surfaces and is self-cleaning.  In other words, real spider-man suits are a long time coming.