Introduction

The structure-function relations in soft matters in food, pharmaceutics, cosmetics, paintings, etc. are still elusive, requiring deeper understanding at the mesoscale. Microrheology is an emerging technique that uses small tracer particles to probe the mechanical response of colloidal solutions at a micron length scale or smaller. It is more sensitive to weak responses than bulk rheology and probes higher-frequency regions, providing viscoelastic parameters such as the storage modulus(G’) and the loss modulus (G”).