title: Resonance frequency and mass identification of zeptogram-scale nanosensor based on the nonlocal beam theory.
abstract: Free vibration and mass detection of carbon nanotube-based sensors are studied in this paper. Since the mechanical properties of carbon nanotubes possess a size effect, the nonlocal beam model is used to characterize flexural vibration of nanosensors carrying a concentrated nanoparticle, where the size effect is reflected by a nonlocal parameter. For nanocantilever or bridged sensor, frequency equations are derived when a nanoparticle is carried at the free end or the middle, respectively. Exact resonance frequencies are numerically determined for clamped-free, simply-supported, and clamped-clamped resonators. Alternative approximations of fundamental frequency are given in closed form within the relative error less than 0.4%, 0.6%, and 1.4% for cantilever, simply-supported, and bridged sensors, respectively. Mass identification formulae are derived in terms of the frequency shift. Identified masses via the present approach coincide with those using the molecular mechanics approach and reach as low as 10(-24)kg. The obtained results indicate that the nonlocal effect decreases the resonance frequency except for the fundamental frequency of nanocantilever sensor. These results are helpful to the design of micro/nanomechanical zeptogram-scale biosensor.
authors.affiliation: School of Civil Engineering, Central South University, Changsha 410075, PR China; State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, PR China. Electronic address: xfli@csu.edu.cn.
authors.forename: Xian-Fang
authors.initials: XF
authors.lastname: Li
authors.affiliation: College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, PR China.
authors.forename: Guo-Jin
authors.initials: GJ
authors.lastname: Tang
authors.affiliation: College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, PR China.
authors.forename: Zhi-Bin
authors.initials: ZB
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Kang Yong
authors.initials: KY
authors.lastname: Lee
mesh_terms: D053758:Nanoparticles; D037742:Nanotubes, Carbon; D014732:Vibration
chemical_list: D037742:Nanotubes, Carbon
keywords: Carbon nanotube-based sensor; Frequency shift; Mass identification; Nonlocal elasticity; Resonance frequency