A stress-controlled shear cell for small-angle light scattering and microscopy

TL;DR

This paper introduces a novel stress-controlled shear cell compatible with microscopy and light scattering, enabling simultaneous rheological and microscopic analysis of soft materials under shear stress.

Contribution

The paper presents a new shear cell design with minimized friction and inertia effects, allowing combined microscopic and rheological measurements under controlled stress conditions.

Findings

Successful coupling with optical microscopy and light scattering.

Effective performance in oscillating and step stress tests.

Accurate measurement of rheological and structural properties.

Abstract

We develop and thoroughly test a stress-controlled, parallel plates shear cell that can be coupled to an optical microscope or a small angle light scattering setup, for simultaneous investigation of the rheological properties and the microscopic structure of soft materials under an imposed shear stress. In order to minimize friction, the cell is based on an air bearing linear stage, the stress is applied through a contactless magnetic actuator, and the strain is measured through optical sensors. We discuss the contributions of inertia and of the small residual friction to the measured signal and demonstrate the performance of our device in both oscillating and step stress experiments on a variety of viscoelastic materials.