Although fish are believed to be entirely covered in scales, some of them, such as the Cave-dwelling Mexican fish, have no eyes to speak of and, therefore, must rely on something to guide them through underwater mazes. As an evolutionary response to this problem, they evolved hair linings on both sides of the body, which allows them to feel the way water is moving around them.
Now, researchers want to mimic this type of receptors, for use on Autonomous Underwater Vehicles (AUV). The main advantage of employing such a technology is that it will significantly reduce the fuel consumption on these crafts, by allowing them to feel currents and "hitch" a ride with them, much as fish do, and it will also enable them to detect strong turbulences and plot the correct route, so as to minimize drag.
In order to do this, scientists at the Georgia Institute of Technology in Atlanta, US, led by Michael McConney and Vladimir Tsukruk, working in collaboration with a team at the Northwestern University in Illinois, led by Chang Liu, created hair fibers, of about 500 micrometers long, using regular polymers. The fibers will be placed on a piezoelectric material that will register faint electrical signals emitted by the "hair," when water passes by.
Their natural sensitivity was improved by adding a special gel that makes the fibers even more like fish receptors, thus increasing their sensitivity by up to 40 percent. The researcher say that, although the hair is longer than that of fish, it should be that way, in order to fully understand what is going on outside the craft, which is meters-long.
The main problem now lies with creating a "brain," a piece of software so advanced that it will understand and analyze impulses coming from hundreds, if not thousands of hair fibers in real-time. The processing power required will be enormous, but the scientists say that the benefits outweigh the costs of development several times-fold.