Ultimate-Exotics.com

There is always something new happening in the world of science. In fact, there are so many new scientific discoveries and inventions, that it’s virtually impossible to stay abreast of all the new information. Here are a few really cool new inventions that are under development.

Artificial gecko feet using carbon nanotubes

Scientists have been trying to duplicate the adhesiveness of gecko feet for years without success.  Liming Dai, a professor at the University of Dayton, and Zhong Wang, director of the Center for Nanostructure Characterization at Georgia tech, have developed a new adhesive that closely mimics the structures on gecko feet. 

Gecko feet are covered with millions of micro-scale hairs which branch into even smaller hairs.  The hairs each have a weak electrical interaction with a surface, and add up to a strong force over the area of the foot. 

The researches came up with an adhesive made of carbon nanotubes whose structure closely resembles that of gecko feet. The material is 10 times more adhesive than the geckos’ feet and it’s easy to lift back up.

Dai’s group, using a silicon substrate, grew arrays of vertically aligned carbon nanotubes topped with an unaligned layer of nanotubes, like rows of trees with branching tops. The adhesive force of these nanotube arrays is very strong, about 100 newtons per square centimeter.  That’s enough for a .15 inch x .15 inch square to support a 3 pound weight. The adhesive properties stayed the same when tested on surfaces, including glass plates, polymer films, and rough sandpaper.

One problem with these materials is that when the material gets dirty they don’t work well. No one has been able to do that. Dai says that carbon nanotubes’ versatility may help overcome the dirt problem. Dai is developing adhesive nanotube arrays that have the nanotubes coated with proteins that change their shape in response to temperature changes. The idea is that robot feet could heat up when they get clogged, sloughing off the dirt so that it can keep walking.