Design strategies for controlling damping in micromechanical and nanomechanical resonators

Sherman Hung,Surabhi Joshi,Srikar Vengallatore

doi:10.1140/epjti5

Abstract

Damping is a critical design parameter for miniaturized mechanical resonators used in microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS), optomechanical systems, and atomic force microscopy for a large and diverse set of applications ranging from sensing, timing, and signal processing to precision measurements for fundamental studies of materials science and quantum mechanics. This paper presents an overview of recent advances in damping from the viewpoint of device design. The primary goal is to collect and organize methods, tools, and techniques for the rational and effective control of linear damping in miniaturized mechanical resonators. After reviewing some fundamental links between dynamics and dissipation for systems with small linear damping, we explore the space of design and operating parameters for micromechanical and nanomechanical resonators; classify the mechanisms of dissipation into fluid–structure interactions (viscous damping, squeezed-film damping, and acoustic radiation), boundary damping (stress-wave radiation, microsliding, and viscoelasticity), and material damping (thermoelastic damping, dissipation mediated by phonons and electrons, and internal friction due to crystallographic defects); discuss strategies for minimizing each source using a combination of models for dissipation and measurements of material properties; and formulate design principles for low-loss micromechanical and nanomechanical resonators.

Highlights

Damping has been studied for well over a hundred years, the rational design and control of structural damping has seemed a distant goal to many generations of engineers
During the past 15 years, there has been a remarkable resurgence of interest in structural damping, especially at small length scales (1 nm to 100 μm), motivated by a host of emerging technologies that include microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS), nanomechanical sensors, and optomechanical systems
The section reviews the fundamental relationships between dissipation and structural dynamics for systems with small linear damping

Summary

Introduction

Damping has been studied for well over a hundred years, the rational design and control of structural damping has seemed a distant goal to many generations of engineers. Our goal is to collect methods and techniques that can provide designers with guidelines and tools for analyzing, controlling, and minimizing damping in miniaturized resonators To this end, the section reviews the fundamental relationships between dissipation and structural dynamics for systems with small linear damping. The dissipation spectra rarely exhibit the Debye peak predicted by Eq (2); instead, internal friction is often a weak monotonic function of frequency [9] Explanations for this behavior range from a distribution of activation energies and relaxation times [5,9], to a hierarchically constrained sequence of serial relaxation processes in which the fast degrees of freedom (involving the motion of single atoms) must relax

C T γ2 ρ v2

Woodhouse J

Findings

43. Zener C: Internal friction in solids I