A simple strobe to study high-order harmonics and multifrequency oscillations in mechanical resonators

TL;DR

This paper introduces a straightforward strobe setup using standard lab equipment to visualize high-order modes and multifrequency oscillations in micromechanical resonators, aiding education and research.

Contribution

It presents a simple, accessible method for studying complex resonator dynamics, suitable for educational demonstrations and experimental analysis.

Findings

Successful visualization of first and second flexural eigenmodes

Demonstration of multifrequency oscillations

Applicable with standard optical microscopes

Abstract

A simple strobe setup with potential to study higher-order eigenmodes and multifrequency oscillations in micromechanical resonators is described. It requires standard equipment, commonly found in many laboratories, and it can thus be employed for public demonstrations of mechanical resonances. Moreover, the work presented here can be used by undergraduate students and/or teachers to prepare practical works in laboratory courses at physics or engineering universities. The dynamics of a micromachined cantilever is analysed as an example. In fact, using our stroboscopic setup, the first and the second flexural eigenmodes as well as a multifrequency oscillation composed by a superposition of both modes have been successfully filmed with a conventional optical microscope equipped with a digital camera.