A multi-axis confocal rheoscope for studying shear flow of structured fluids

TL;DR

This paper introduces a novel confocal rheoscope capable of applying uniform uniaxial or biaxial shear to structured fluids, enabling real-time stress measurement and 3D imaging for advanced rheological studies.

Contribution

The paper presents a new confocal rheoscope design that allows precise biaxial shear and confinement control, integrating high-speed imaging and force measurement.

Findings

Enables uniform biaxial shear with adjustable gap down to 2 μm

Allows simultaneous real-time biaxial stress measurement and 3D imaging

Facilitates advanced studies of colloidal suspension rheology

Abstract

We present a new design for a confocal rheoscope that enables uniform uniaxial or biaxial shear. The design consists of two precisely-positioned parallel plates with a gap that can be adjusted down to 2$\pm$0.1 \mu m, allowing for the exploration of confinement effects. By using our shear cell in conjunction with a biaxial force measurement device and a high-speed confocal microscope, we are able to measure the real-time biaxial stress while simultaneously imaging the material 3D structure. We illustrate the importance of the instrument capabilities by discussing the applications of this instrument in current and future research topics in colloidal suspensions.