Arrays of cricket-inspired sensory hairs with capacitive motion detection

Abstract

This paper presents the fabrication of flow-sensors based on the drag-force induced motion of artificial hairs connected to capacitive read-out. Artificial hairs were made either out of moulded silicon-nitride structures or by SU-8. The SU-8 hairs were suspended on membranes containing electrodes to form the variable capacitors. Silicon-rich-nitride hairs were made using a silicon wafer as a dissolvable mould. The longest SU-8 hairs were fabricated using a 470 /spl mu/m thick photoresist layer. Capacitance versus voltage, frequency dependency and directional sensitivity measurements have been carried out on entire arrays and are reported in this paper.