Colloids in Active Fluids: Anomalous Microrheology and Negative Drag

G. Foffano, J. S. Lintuvuori, K. Stratford, M. E. Cates, D. Marenduzzo

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

We simulate an experiment in which a colloidal probe is pulled through an active nematic fluid. We find that the drag on the particle is non-Stokesian (not proportional to its radius). Strikingly, a large enough particle in contractile fluid (such as an actomyosin gel) can show negative viscous drag in steady state: the particle moves in the opposite direction to the externally applied force. We explain this, and the qualitative trends seen in our simulations, in terms of the disruption of orientational order around the probe particle and the resulting modifications to the active stress.

Original languageEnglish
Article number028103
Number of pages5
JournalPhysical Review Letters
Issue number2
Publication statusPublished - 13 Jul 2012


Dive into the research topics of 'Colloids in Active Fluids: Anomalous Microrheology and Negative Drag'. Together they form a unique fingerprint.

Cite this