Carbon nanotubes made to stick like a gecko’s foot

Renowned for their ability to walk up walls like miniature Spider-Men–or even to hang from the ceiling by one toe–the colorful lizards of the gecko family owe their wall-crawling prowess to their remarkable footpads. Each five-toed foot is covered with microscopic elastic hairs called setae, which are themselves split at the ends to form a forest of nanoscale fibers known as spatulas. So when a gecko steps on almost anything, these nano-hairs make such extremely close contact with the surface that they form intermolecular bonds, thus holding the foot in place.

Now, polymer scientist Ali Dhinojwala of the University of Akron and his colleagues have shown how to create a densely packed carpet of carbon nanotubes that functions like an artificial gecko foot–but with 200 times the gecko foot’s gripping power. Potential applications include dry adhesives for microelectronics, information technology, robotics, space and many other fields.

The group’s work was funded by the National Science Foundation, and is reported in a recent issue of the journal Chemical Communications.