Oscillation control of carbon nanotube mechanical resonator by electrostatic interaction induced retardation.

Masaaki Yasuda,Takayuki Arie,Seiji Akita,Kuniharu Takei

doi:10.1038/srep22600

Abstract

Despite the superb intrinsic properties of carbon nanotube mechanical resonators, the quality factors at room temperature are 1,000 or less, even in vacuum, which is much lower than that of mechanical resonators fabricated using a top-down approach. This study demonstrates the improvement of the quality factor and the control of nonlinearity of the mechanical resonance of the cantilevered nanotube by electrostatic interaction. The apparent quality factor of the nanotube supported by insulator is improved drastically from approximately 630 to 3200 at room temperature. Results show that retardation of the electrostatic force induced by the contact resistance between the nanotube and the insulator support improves the quality factor. Finite element method calculation reveals that the nonuniform pileup charge on the insulator support strongly influences the nonlinearity of the resonance.

Highlights

Post-annealing treatment at temperatures higher than 1500 °C
Regarding control experiments without or less charge accumulation on the SU-8, optical measurements were performed in vacuum (~10−4 Pa) at room temperature, where the frequency response of scattered light from the vibrating Carbon nanotube (CNT) cantilever irradiated by the focused laser beam were measured through an optical aperture[13,17,33]
The Q-factor without the e-beam charge accumulation obtained from the optical method is ~630, which is comparable to the reported values for CNTs supported on the conductive substrate measured from the scanning electron microscope (SEM) image[18,19,34], where the nonlinear response was hardly observed

Summary

Introduction

The Q-factor without the e-beam charge accumulation obtained from the optical method is ~630, which is comparable to the reported values for CNTs supported on the conductive substrate measured from the SEM image[18,19,34], where the nonlinear response was hardly observed. Note that the kink structure observed in SEM images shown in Fig. 1b induces very few nonlinear or Q- enhancement effects under small vibration amplitude regime in our experimental condition, because the CNT with kink structure can be treated as a single spring consisting of a series connection of tiny springs with different spring constants (see “Supporting information” for more detail).

Results

Conclusion