Scientists from across the world have spent years trying to figure out the way geckos climb. Now, researchers at Stanford University have discovered an adhesive that makes it possible for humans to scale vertical glass, just like a gecko climbs. The hand-sized silicone pads even more adhesive strength than geckos. The biggest challenge was the issue of scaling. A gecko weighs about 200g, but a human male weighs about 75 kg on average. Stanford scientists’ gloves handle it without any loss of performance.
A gecko harnesses the van der Waals forces
Led by Dr Elliot Hawkes, researchers applied the same attraction and repulsion forces that geckos use. These forces are called van der Waals forces. Though it’s a very weak force, its effect is multiplied across the thousands of tiny hairs covering a gecko’s toes. It allows them to stick to surfaces firmly. Geckos have adhesive pressures of 6.8-13.6kg per square inch for each limb. That means they can easily hand their whole body with one toe.
Researchers created small tiles called microwedges to harness the power of van der Waals forces. It’s not an untested technology. Scientists tested the pads over a hundred of times without any failure. During tests, a 70kg man used 140 sq cm silicone pads to climb a 12-foot high vertical glass successfully. He scaled up the heights just like Spiderman scales skyscrapers.
Darpa has also developed another glove
However, the gecko-inspired gloves work only on smooth, clean surfaces. Stanford scientists are already working to create a self-cleaning adhesive pad, mimicking the way geckos maintain their own sticky feet. It was developed in collaboration with the U.S. Defense Advanced Research Projects Agency (Darpa). The agency is developing biologically-inspired climbing aids for soldiers under its Z-Man program.
Earlier this year, Darpa showcased a climbing device that lets a person scale a glass wall. The gloves were coated with a specialized material called Geckskin, which clings to surfaces the same way the geckos do. That device was developed by Draper Laboratory in Cambridge, Massachusetts.
Stanford scientists published findings of their study in the journal The Royal Society Interface.