Implications of vibration characteristics towards mass detection using graphene nanoribbon-based bridge configured mass sensor

Abstract

Owing to its astounding mechanical properties, graphene nanoribbon (GNR) based nano-resonator is aimed as mass sensor with doubly clamped nano beam subjected to pair of point masses adsorbed at different positions over its surface. Though pristine GNR is revealed with non-piezoelectric behaviour inherently, it can be turned into piezoelectric by suitable adatoms. The present analysis investigates the performance of monolayer based (F-, Li- and K-) doped GNRs in the form of vibration attributes such as eigen-frequencies, Q-factor and Force sensitivities. Euler-Bernoulli thin beam theory is applied to model the doped GNR. The obtained results highlight the shift in the eigen-frequency due to adsorbed masses and their positions over the surface of GNRs. Moreover, the Q-factor and Force sensitivities are also determined for the proposed mass sensors. The results indicate that the eigen-frequencies at higher modes are insignificant to the Q-factor. For the fundamental mode, the magnitude of Q-factor varies in the range of 4.39–4.52 for the proposed mass sensor with respect to the positions and magnitudes of pairs of masses. The force sensitivity for the doped GNR is attained at a level of aN/√Hz. Though, force sensitivity rises with the eigen-modes, the sensitivity with the minimum magnitude to be preferred for a sensor as it reflects to early detection of mass. This suggests the fundamental mode to operate the mass sensor. For the fundamental mode, the sensitivity of Li doped GNR is ranging from 103.60–117.58 aN/√Hz, while it is ranging from 109.67 to 124.45 aN/√Hz and 125.31–142.20 aN/√Hz for K- and F- doped GNRs, respectively. The results of the present work are compared with the available literatures. From the results, significant effect of adatom is observed on the vibration characteristics of the GNRs. The findings of the present work can significantly be used to design the GNR based bridge configured mass sensor.