Fish sensor

Researchers at Georgia Tech have built a motion detector by copying the way that the blind cavefish senses the movement of water around it through the use of the gel-covered hairs that cover its body.

Vladimir Tsukruk, a professor at the Georgia Tech School of Materials Science and Engineering, and graduate students Michael McConney and Kyle Anderson conducted preliminary experiments with a simple artificial hair cell microsensor made of a common epoxy-based polymer called SU-8.

They found that, by itself, the sensor could not achieve the high-sensitivity or long-range detection of hydrodynamic disturbances created by moving or stationary bodies in a flow field. The hair cell needed a gel-like capsule - called a cupula - to overcome these challenges, similar to the one found on the fish itself.

'After covering the hair cell with synthetic cupula, our bio-inspired microsensor had the ability to detect flow better than the blind fish. The fish can detect flow slower than 100 micrometres per second, but our system demonstrated flow detection of several micrometres per second,' said Tsukruk. 'Adding the cupula allowed us to detect a much smaller amount of flow and expand the dynamic range because it suppressed the background noise.'