Design and characterization of a low-vibration laboratory with cylindrical inertia block geometry

TL;DR

This paper presents a novel cylindrical inertia block design for vibration isolation in nanofabrication labs, achieving higher resonance frequencies than traditional rectangular blocks, thus improving environmental noise suppression.

Contribution

The study introduces a cylindrical inertia block geometry that enhances vibration isolation by increasing fundamental resonance frequency compared to rectangular designs.

Findings

Resonance frequency of 249 Hz achieved

Finite element analysis matches experimental measurements

Cylindrical design outperforms rectangular in frequency

Abstract

Many modern nanofabrication and imaging techniques require an ultra-quiet environment to reach optimal resolution. Isolation from ambient vibrations is often achieved by placing the sensitive instrument atop a massive block that floats on air springs and is surrounded by acoustic barriers. Because typical building noise drops off above 120 Hz, it is advantageous to raise the flexural resonance frequencies of the inertia block and instrument far above 120 Hz. However, it can be challenging to obtain a high fundamental frequency of the floating block using a simple rectangular design. Here we design, construct, and characterize a vibration isolation system with a cylindrical inertia block, whose lowest resonance frequency of 249 Hz shows good agreement between finite element analysis simulation and directly measured modes. Our simulations show that a cylindrical design can achieve higher fundamental resonance frequency than a rectangular design of the same mass.