# Measuring storage and loss moduli using optical tweezers: broadband microrheology

## TL;DR

This paper introduces a method using optical tweezers and a generalized Langevin equation to measure the broadband viscoelastic properties of complex fluids, covering a wide frequency range.

## Contribution

It presents a novel experimental procedure for broadband microrheology with optical tweezers, enabling comprehensive measurement of viscoelastic moduli.

## Key findings

- Successful measurement of storage and loss moduli across a broad frequency spectrum
- Application of generalized Langevin equation to relate particle trajectories to fluid properties
- Enhanced capability for microrheological analysis using optical tweezers

## Abstract

We present an experimental procedure to perform broadband microrheological measurements with optical tweezers. A generalised Langevin equation is adopted to relate the time-dependent trajectory of a particle in an imposed flow to the frequency-dependent moduli of the complex fluid. This procedure allows us to measure the material linear viscoelastic properties across the widest frequency range achievable with optical tweezers.