Analytic modeling and piezoresistive detection theory of acoustic resonances in carbon nanotubes

This paper presents a direct electrical measurement technique of mechanically vibrating single-walled carbon nanotubes (SWCNTs) actuated up to microwave L-Band frequency regime. Acoustic resonances of suspended SWCNTs are detected by means of inherent average strain (<;ε>;) dependent piezoresistive property of the nanotubes. A novel combination of capacitive drive and piezoresistive sensing eliminates the high-frequency measurement barrier associated with large contact resistance (R_C) and capacitance (C_C). We demonstrate via analytic modeling, with input parameters from previously fabricated semiconducting and small-gap semiconducting (SGS) CNTs that this detection mechanism is feasible to characterize resonating CNTs up to beyond Ultra High Frequency (UHF) range.