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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:57 |
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Conference: Bucharest University Faculty of Physics 2012 Meeting
Section: Atomic and Molecular Physics; Astrophysics
Title:
Single carbon nanotubes as nanosensors for molecular mass detection
Authors:
G.KOSA, M.BERCU, V.GRECU
Affiliation:
Faculty of Physics, University of Bucharest, Magurele, Romania.
E-mail
mircea_bercu2@yahoo.com; dolomynum@gmail.com
Keywords:
carbon nanotubes, nanosensors, femtobalance, zeptobalance, molecular dynamics
Abstract:
Carbon nanotube resonators in cantilevered and bridge configurations can be used for detecting molecular masses, as recent publications revealed. This study uses an original package based on molecular dynamics method. We have developed large atomistic models of thousands of atoms to simulate the elastic behaviour of both cantilevered and bridge (5, 5) SWCNT, with lengths in range of 10 nm - 30 nm. Forced transversal oscillation at a fixed frequency is applied at an end of SWCNT with the other one fixed. The spectra of the oscillation modes were calculated by extracting the position versus time of the mass centre corresponding to a specific unit cell of the carbon nanotube. Fourier transform of these data reveals the frequency spectra and the amplitudes of the longitudinal and transversal oscillations. The extra-mass added to the carbon nanotube produces frequency red-shifts calculated in the frame of the computation approach. Simulations indicate shifts from 2.5 to 2 GHz of cantilever configuration, and from 26.5 GHz to 5.5 GHz of bridged SWCNT, when the extra-mass changes from 10-26 kg to 10-21 kg, respectively. We also analysed the effect on femto-balance sensitivity of the extra-mass distribution and the applied strain.
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