Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version



Suggested Citation:
Gao, T., Hu, H. H., & Castañeda, P. P. (2012) Shape Dynamics and Rheology of Soft Elastic Particles in a Shear Flow. Physical Review Letters, 108, 058302.

© 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physical Review Letters and may be found at


The shape dynamics of soft, elastic particles in an unbounded simple shear flow is investigated theoretically under Stokes flow conditions. Three types of motion—- steady-state, trembling, and tumbling—- are predicted, depending on the shear rate, elastic shear modulus, and initial particle shape. The steady-state motion is found to be always stable. In addition, the existence of a trembling regime is documented for the first time in nonvesicle systems, and a complete phase diagram is developed. The rheological properties of dilute suspensions of such soft particles generally exhibit shear-thinning behavior and can even display negative intrinsic viscosity for sufficiently soft particles.



Date Posted: 02 February 2012

This document has been peer reviewed.