The dynamics of an externally driven nanoscale beam that is under high tension and immersed in a viscous fluid

TL;DR

This paper presents a comprehensive theoretical model for the dynamics of a high-tension nanoscale beam immersed in viscous fluids, validated by experiments in air and water, highlighting the beam's mode behavior under external driving forces.

Contribution

The study introduces a unified theoretical framework that accounts for all tension levels, higher mode motion, and localized harmonic driving, validated through experimental comparisons.

Findings

Good agreement between theory and experiments in air and water.

Simplified string approximation effectively describes the beam dynamics.

Model captures the influence of high tension and viscous damping on beam motion.

Abstract

We explore the dynamics of a nanoscale doubly-clamped beam that is under high tension, immersed in a viscous fluid, and driven externally by a spatially varying drive force. We develop a theoretical description that is valid for all possible values of tension, includes the motion of the higher modes of the beam, and accounts for a harmonic force that is applied over a limited spatial region of the beam near its ends. We compare our theoretical predictions with experimental measurements for a nanoscale beam that is driven electrothermally and immersed in air and water. The theoretical predictions show good agreement with experiment and the validity of a simplified string approximation is demonstrated.