Session: MNS-02-02 Dynamics of M/NEMS

Paper Number: 68229

Start Time: August 18, 03:20 PM

68229 - Nonlinear Damping in Graphene Nanomechanical Systems 

Micro/Nano-mechanical systems are utilized in many technologies and often have been used for their sensing capabilities.
An ideal framework for sensitive nanomechanical devices is 2-D materials, and especially graphene, due to its exceptional
mechanical, electrical and thermal properties. By their atomically thin nature, these systems are fundamentally nonlinear.
In addition to the geometric nonlinearities, nonlinear energy decay mechanisms have been observed in these systems [1]. Nonlinear damping in these devices is a fundamental limitation to their sensing capabilities yet its full understanding is an open question. Among different dissipation mechanisms, an important factor that is hypothesized to affect damping properties of graphene nanodrums is the intermodal couplings [2]. The microscopic theory of mechanical dissipation suggests that nonlinear damping of a resonant mode can be strongly enhanced when it is coupled to a vibration mode that is close to twice its resonance frequency [3]. To date, no experimental evidence of this enhancement has been realized. In this work [4], we experimentally show that nanoresonators driven into parametric-direct internal resonance provide supporting evidence for the microscopic theory of nonlinear dissipation. We optothermally modulate the tension of a graphene membrane in order to activate parametric resonance with a blue laser, and read-out using a red laser, whose reflected intensity is modulated by the motion of the nanodrum in a Fabry–Pérot etalon formed by the graphene and the back mirror. By regulating the drive level, we tune the parametric resonance of a graphene nanodrum over a range of 40–70 MHz to reach successive two-to-one internal resonances, leading to a nearly two-fold increase of the nonlinear damping. The described mechanism can isolate and differentiate mode coupling induced nonlinear damping from other dissipation sources, and sheds light on the origins of nonlinear dissipation in nanomechanical resonators. Our study[4] opens up a route towards utilizing modal interactions and parametric resonance to controllably tune nonlinear damping which complements existing methods for tuning linear damping, linear stiffness, and nonlinear stiffness, extending our toolset to adapt and study the rich nonlinear dynamics of nanoresonators.

 

[1] A. Eichler, J. Moser, J. Chaste, M. Zdrojek, I. Wilson-Rae and A. Bachtold, "Nonlinear damping in mechanical resonators made from carbon nanotubes and graphene," Nature Nanotechnology, vol. 6, no. 6, pp. 339-342, 2011.

[2] D. Midtvedt, A. Croy, A. Isacsson, Z. Qi and H. S. Park, "Fermi-Pasta-Ulam Physics with Nanomechanical Graphene Resonators: Intrinsic Relaxation
and Thermalization from Flexural Mode Coupling," Physical Review Letters, vol. 112, no. 14, p. 145503, 2014.

[3] Dykman, M. & Krivoglaz, M. Spectral distribution of nonlinear oscillators with nonlinear friction due to a medium. Phys. Status Solidi 68, 111–123 (1975).

[4] Keşkekler, A., Shoshani, O., Lee, M. et al. Tuning nonlinear damping in graphene nanoresonators by parametric–direct internal resonance. Nat Commun 12, 1099 (2021).

 

Presenting Author: Ata Keşkekler TU Delft

Authors:

Ata Keşkekler TU Delft
Oriel Shoshani Ben-Gurion University of the Negev
Peter G. Steeneken TU Delft
Farbod Alijani TU Delft