Adaptation for Frequency Focusing and Increased Sensitivity in Biomimetic Flow Sensors using Electrostatic Spring Softening

Abstract

This paper presents the results of active adaptation of sensor sensitivity. By applying a DC-bias voltage to the sensing electrodes of a cricket inspired artificial hair sensor the effective spring stiffness can be adapted resulting in a reduced resonance frequency and increased sensitivity. An array of flow sensors was actuated using electrical and acoustical signals at different values of the DC-bias voltage. Characterization was done using a scanning laser vibrometer. Both resonance frequency versus applied DC-bias voltage and deflection-amplitude versus DC-bias voltage behave well in accordance to theory and show that adaptation by DC-biasing can be used for frequency focusing and increasing sensitivity.

Improving the performance of biomimetic hair-flow sensors by electrostatic spring softening

“…Here, we report the use of electrostatic spring softening (ESS) to increase the sensitivity and enhance the mechanical response of these sensors [20]. Previously, the possibility of ESS for flow sensors by dc-bias voltages was demonstrated using electrostatic actuation [21]. In this work, we show that ESS can be used to adaptively change the mechanical transfer function of the system.…”

Lowering the sensory threshold and enhancing the responsivity of biomimetic hair flow sensors by electrostatic spring softening

“…To increase the sensitivity and enhancing the mechanical transfer of these sensors, we make use of Electrostatic Spring Softening (ESS). Previously, the use of ESS was demonstrated for electrostatically actuated flow sensors [4]. In this work, we show that ESS is indeed applicable to adaptively change the electro-mechanical properties of the system for oscillating air flow perception.…”

Learning from crickets: artificial hair-sensor array developments

“…Therefore next generation arrays will be fitted with lower hairdensity. This is a lesson that could be easily learned from studies of the cricket cerci as well since relative inter-hair distances seem to peak between 5 and 7 hair-diameters [34], as opposed to the 3 -5 hair-diameters of some of our previous designs [35].…”