An air flow sensor modeled on wind receptor hairs of insects

Abstract

A new conceptual air flow sensor modeled on wind-receptor hairs of insects which can detect low velocity air flow is demonstrated. Since the viscous force is dominant at micro size, the velocity of air flow can be determined by measuring the force on a sensory hair. Two mechanical structures modeled on insect sensory hairs have been fabricated. An array of a 1-DOF (Degree Of Freedom) sensory hairs has selectivity of frequencies. A 2-DOF sensory hair array can detect the direction angle of air flow. Both sensors have cantilevers and strain gauges fabricated at the bottom of the sensory hairs. The output voltage was proportional to the velocity of air flow in good agreement with the theory. Both the 1-DOF sensory hair and the 2-DOF sensory hair arrays detected the velocity of air flow from several tens of cm/s to 2 m/s. Also, the 2-DOF sensory hair array detected the direction angle of 360 degrees as a function of a sinusoidal curve.