Bulk Rheology

Analyzing the viscoelasticity of complex formulations in a non-destructive manner offers a better understanding of the network and structure of the product. Classical methods of viscosity determination require to apply a stress to the system, this may cause a perturbation of the network and thus the non-representative analysis of the actual structure.

Rheolaser Master uses Diffusing Wave Spectroscopy (DWS) to monitor particle mobility. The technique consists of sending a laser beam into the sample to measure Brownian motion. Particle Mean Square Displacement calculated from Brownian motion depends on the viscoelastic structure of the sample. Particle mobility is given in the nanometric scale allowing a high sensitivity in the assessment of viscoelastic properties.

Using a non-contact, optical method allows measuring bulk rheology without any mechanical stress. The measurement is performed at rest, allowing structure evolution to be monitored. A closed glass cell prevents any evaporation or drying and makes it safe to always operate, ensuring an easy sample handling and data treatment process.

  • Measurement at rest (no mechanical stress)

  • Viscoelastic properties vs. time

  • Easy sample handling and data treatment

How does it work?


Rheolaser Master enables the acquisition of Mean Square Displacement (MSD) curves as a function of time or temperature, allowing to monitor stability or gelling process. Any kind of gelling process can be studied, regardless of gel variable. Quantitative parameters such as elasticity and viscosity are assessed in terms of liquid solid equilibrium, and elasticity and macroscopic viscosity indexes.


Viscoelastic properties measured with Rheolaser Master are a perfect tool for milk gel analysis, such as yogurts and cheeses. Especially the assessment of textural parameters of yogurts as a function of ingredients is a valuable tool for the development of new recipes. In cheese technologies, the non-contact monitoring helps to optimize process and formula parameters.