Chinese-led Research Team Creates Bionic Gecko Feet
A U.S. research team led by Chinese scientists has created a nanotube-based dry adhesive that surpasses the stickiness of gecko feet – no easy feat, since the animals can cling to nearly any type of surface.
Geckos rely on aligned microscopic hairs for their gravity-defying climbs. The research team’s design mimics this arrangement, with a vertically aligned array of straight carbon nanotubes topped by a layer of curly, entangled nanotubes, explains Wang Zhonglin, the lead researcher from the Georgia Institute of Technology.
As with gecko feet, the combination produces an adhesive with superior strength when clinging against the pull of gravity, and regular strength in a normal, perpendicular direction, allowing the adhesive to be easily pulled away from a surface. The shear adhesive force of the nanotube array is almost 10 times that of a gecko’s foot.
Though the material might seem most appropriate for use by Spider-man, real applications may be less glamorous. Because carbon nanotubes conduct heat and electrical current, the bionic gecko feet could be used to connect electronic devices. Another application might be for adhesives that work long-term in space. “In the vacuum of space traditional kinds of adhesives dry out, but nanotube dry adhesives would not be bothered by this environment,” said Dai Liming, another lead researcher from the University of Dayton. |