Tuning the Resonance Properties of 2D Carbon Nanotube Networks towards Mechanical Resonator

TL;DR

This study uses molecular dynamics simulations to explore how to optimize the resonance properties of single wall carbon nanotube networks for use as high-quality nanoresonators, focusing on strain and structural modifications.

Contribution

It demonstrates that applying axial strain and modifying connecting structures can significantly enhance the quality factor of SWNT networks as nanoresonators.

Findings

High natural frequency inherited from SWNTs

Vibration modes can be suppressed by axial strain

Achieved quality factor of approximately 10^9 with 2% tensile strain

Abstract

The capabilities of the mechanical resonator-based nanosensors in detecting ultra-small mass or force shifts have driven a continuing exploration of the palette of nanomaterials for such application purpose. Based on large-scale molecular dynamics simulations, we have assessed the applicability of a new class of carbon nanomaterials for the nanoresonator usage, i.e., the single wall carbon nanotube (SWNT) network. It is found that the SWNT networks inherit the excellent mechanical properties from the constituent SWNTs, possessing a high natural frequency. However, although a high quality factor is suggested from the simulation results, it is hard to obtain an unambiguous Q-factor due to the existence of vibration modes in addition to the dominant mode. The nonlinearities resulting from these extra vibration modes are found to exist uniformly under various testing conditions including different initial actuations and temperatures. Further testing shows that these modes can be effectively suppressed through the introduction of axial strain, leading to an extremely high quality factor in the order of 109 estimated from the SWNT network with 2% tensile strain. Additional studies indicate that the carbon rings connecting the SWNTs can also be used to alter the vibrational properties of the resulting network. This study suggests that the SWNT network can be a good candidate for the applications as nanoresonators.