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Updated: May 12, 2026
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Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
Nonlinear active micro-rheology in a glass-forming soft-sphere mixture
1Institut für Physik, Johannes-Gutenberg-Universität Mainz, Saarstraße 21, 55099 Mainz, Germany.
The Journal of Chemical Physics
|April 6, 2013
Summary
We simulated a glass-forming liquid, finding a surprising nonlinear response in a pulled particle
Area of Science:
- Condensed matter physics
- Computational materials science
- Statistical mechanics
Background:
- Glass-forming liquids exhibit complex dynamics near the glass transition.
- Understanding particle transport in supercooled liquids is crucial for materials science.
Purpose of the Study:
- To investigate the nonlinear response of a single particle pulled through a glass-forming Yukawa mixture.
- To analyze structural changes and diffusive behavior under external force.
Main Methods:
- Extensive molecular dynamics computer simulations.
- Analysis of pair correlation functions and van Hove correlation functions.
- Measurement of mean-square displacements and steady-state velocity.
Main Results:
- A nonlinear response regime was identified for intermediate forces, with minimal structural changes but significant velocity changes.
- Anisotropic diffusion was observed: anomalous superdiffusion parallel to the force and normal diffusion perpendicular to it.
- A force-temperature superposition principle was found, characterized by a Peclet number.
Conclusions:
- The study reveals distinct dynamic behaviors parallel and perpendicular to the applied force in supercooled liquids.
- Effective temperatures can describe the dynamics of the driven particle.
- Nonlinear rheology in glass-forming systems can occur without significant local structural rearrangement.
