Optimization of Cricket-inspired, Biomimetic Artificial Hair Sensors for Flow Sensing

High density arrays of artificial hair sensors, biomimicking the extremely sensitive mechanoreceptive filiform hairs found on cerci of crickets have been fabricated successfully. We assess the sensitivity of these artificial sensors and present a scheme for further optimization addressing the deteriorating effects of stress in the structures. We show that, by removing a portion of chromium electrodes close to the torsional beams, the upward lift at the edges of the membrane due to the stress, will decrease hence increase the sensitivity.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

HAIR-BASED FLOW-SENSING INSPIRED BY THE CRICKET CERCAL SYSTEM

International audienceMicro electro mechanical system (MEMS) offers exciting possibilities for the fabrication of bioinspired mechanosensors. Over the last years we have been working on cricket inspired hair-sensor arrays for spatio-temporal flow-field observations (i.e., flow-cameras) and source localization. Whereas making flow-sensors as energy efficient as cricket hair-sensors appears to be a real challenge, we have managed to fabricate hair-sensors with sub-millimeter per second flow sensing thresholds, use them in lateral line experiments, address them individually while in arrays, track transient flows, quantify viscous coupling effects and use parametric effects to achieve sharp filtering and amplification. In this research insect biologists and engineers have been working in close collaboration, generating a bidirectional flow of information and knowledge, beneficial to both. For example where the engineering has greatly benefitted from the insights derived from biology and biophysical models, the biologists have taken advantage of MEMS structures allowing for experiments that are hard to do on living materialRead More: http://www.worldscientific.com/doi/abs/10.1142/9789814354936_003

Uncovering signals from measurement noise by electro mechanical amplitude modulation

We present an electromechanical parametric scheme to improve the low-frequency signal-to-noise ratio of energy buffering type transducers. The method is based on periodic modulation of the stiffness in the sensory system which produces upconverted replicas of the signals of interest at frequencies where measurement is less troubled by noise or other detrimental effects. We demonstrate this principle by means of capacitive biomimetic hair flow sensors, where we modulate the rotational spring stiffness by periodic electrostatic spring softening, such that a replica of the original signal is formed around the modulation frequency. Using this replica we gain up to a 25-fold improvement of the low-frequency signal-to-noise ratio and sensing threshold. For transient measurements we demonstrate that tiny signals, which are below the noise-levels in the base-band, are revealed well when upconverted to higher frequencies