Optomechanical non-contact measurement of microparticle compressibility in liquids

TL;DR

This paper introduces a high-throughput, label-free method to measure the compressibility of freely flowing microparticles using opto-mechano-fluidic resonators, enabling detection of neutrally buoyant particles based on their mechanical properties.

Contribution

The study presents a novel optomechanical technique for measuring microparticle compressibility in liquids, expanding detection capabilities beyond density contrast methods.

Findings

Successful measurement of microparticle compressibility in flow

Detection of neutrally buoyant particles based on compressibility contrast

High-throughput, label-free measurement approach

Abstract

High-throughput label-free measurements of the optical and mechanical properties of single microparticles play an important role in biological research, drug development, and related large population assays. Mechanical detection techniques that rely on the density contrast of a particle with respect to its environment are blind to neutrally bouyant particles. However, neutrally buoyant particles may still have a high compressibility contrast with respect to their environment, opening a window to detection. Here we present a label-free high-throughput approach for measuring the compressibility (bulk modulus) of freely flowing microparticles by means of resonant measurements in an opto-mechano-fluidic resonator.