Development of a confocal rheometer for soft and biological materials

TL;DR

This paper presents a confocal rheometer combining a stress-controlled rheometer with a laser scanning confocal microscope, enabling simultaneous measurement of viscoelastic properties and 3D imaging of soft and biological materials.

Contribution

It introduces a straightforward design integrating commercial instruments for concurrent rheological and microscopic analysis of soft materials.

Findings

System preserves the performance of both instruments.

Enables time-resolved 3D imaging during rheological measurements.

Demonstrated with measurements on soft materials.

Abstract

We discuss the design and operation of a confocal rheometer, formed by integrating an Anton Paar MCR301 stress-controlled rheometer with a Leica SP5 laser scanning confocal microscope. Combining two commercial instruments results in a system which is straightforward to assemble that preserves the performance of each component with virtually no impact on the precision of either device. The instruments are configured so that the microscope can acquire time-resolved, three-dimensional volumes of a sample whose bulk viscoelastic properties are being measured simultaneously. We describe several aspects of the design and, to demonstrate the system's capabilities, present the results of a few common measurements in the study of soft materials.