Flow sensors based on hair structures of blind cavefish
Members of the fish species Astyanax fasciatus cannot see, but they sense their environment and the movement of water around them with gel-covered hairs that extend from their bodies; Yellow Jackets researchers develop sensors which mimic the blind fish’s sensors; these sensors could have a variety of underwater applications, such as port security, surveillance, early tsunami detection, autonomous oil rig inspection, autonomous underwater vehicle navigation, and marine research
The 1950s are often regarded as a boring, conformist decade in America — a decade of large cars and suburban expansion, with Dwight Eisenhower, a balding, avuncular, and grammatically challenged serving as president. Pete Seeger made famous a song by Melvina Reynolds called “Little Boxes”:
Little boxes on the hillside, Little boxes made of tickytacky
Little boxes on the hillside, little boxes all the same…
And the people in the houses all went to the university
Where they were put in boxes and they came out all the same.
Little wonder that the historian Arthur Schlesinger Jr. referred to the 1950s as “the bland leading the bland.”
Let us talk, though about the blind leading the blind — or, rather, the blind leading the seeing. More specifically, a blind fish that has evolved a unique technique for sensing motion may inspire a new generation of sensors that perform better than current active sonar. Members of the fish species Astyanax fasciatus cannot see, but they sense their environment and the movement of water around them with gel-covered hairs that extend from their bodies. Their ability to detect underwater objects and navigate through their lightless environment inspired a group of researchers to mimic the hairs of these blind cavefish in the laboratory.
While the fish use these hairs to detect obstacles, avoid predators, and localize prey, researchers believe the engineered sensors they are developing could have a variety of underwater applications, such as port security, surveillance, early tsunami detection, autonomous oil rig inspection, autonomous underwater vehicle navigation, and marine research.
“These hair cells are like well-engineered mechanical sensors, similar to those that we use for balance and hearing in the human ear, where the deflection of the jelly-encapsulated hair cell measures important flow information,” said Vladimir Tsukruk, a professor in the Georgia Tech School of Materials Science and Engineering. “The hairs are better than active sonar, which requires a lot of space, sends out strong acoustic signals that can have a detrimental effect on the environment, and is inappropriate for stealth applications.”
In a presentation on 20 March at the American Physical Society meeting, researchers from Georgia Tech described their engineered motion detector that mimics the underwater flow measurements made by the blind cavefish. This research was sponsored — you guessed it — by the Defense Advanced Research Projects Agency (DARPA).
Tsukruk and graduate students Michael McConney and Kyle Anderson conducted preliminary experiments with a simple artificial hair cell microsensor made of SU-8, a common
