Biomimetic flow sensors for environmental awareness

Crickets possess hairy organs attached to their abdomen, the so-called cerci. These cerci contain highly flow-sensitive mechanosensors that enable the crickets to monitor the flow-field around them and react to specific stimuli form the environment, e.g. air-movements generated by hunting spiders. Salient is the sensitivity of these sensors, which work at thermal noise threshold levels, and the large number of hairs which, together with the necessary neural processing, allows the cricket to use the cerci as a kind of "flow-camera". Biologists and engineers have been working together in the recent past to regenerate part of the outstanding sensing capabilities of crickets in manmade, bio-inspired flow-sensor arrays. Using micro-electromechanical systems (MEMS) technology sensors are created that are sensitive and show a high degree of directivity. By analyzing the governing physics the sensors have been optimized to the point that currently the electronic interfacing is the limiting factor. Arrays of sensors, interfaced using Frequency Division Multiplexing (FDM), have been demonstrated to enable the tracking of the movement of small spheres.