High-Bandwidth and Sensitive Air Flow Sensing Based on Resonance Properties of CNT-on-Fiber Hairs

Abstract

Artificial hair flow sensors were fabricated using piezoresistive, radially grown carbon nanotube arrays on glass fibers and investigated for their dynamic aerodynamic response as measured within an instrumented plane-wave tube. The sensors were experimentally observed to provide both a large bandwidth of operation below first resonance and a strong resonance response at selected frequencies above first resonance. The frequency of first resonance was easily tunable by adjusting the length of the exposed hair and could be made to vary from a few hundred hertz to over 13 kHz. Higher frequency bands were accessible for a given hair length using higher-order resonance modes, up to five of which were observed. All of the responses were understood and modeled using a vibrating Euler-Bernoulli beam analysis.

Keywords

• CNT
• hair flow sensor
• vibration resonance frequency
• Euler-Bernouli
• cantilever
• piezoresistive
• harmonic oscillator