Separations of micro and nano particle suspensions in viscoelastic fluids

Interdisciplinary Areas: Engineering-Medicine, Micro-, Nano-, and Quantum Engineering

Project Description

Confined, multicomponent suspensions are common in many biomedical contexts, for example when one tries to separate blood from platelets and white blood cells.  Researchers are starting to use polymer additives to aid in continuous, high throughput separations, and there is a need to unravel the role of fluid rheology, geometry, and flow rate on the dynamics of the particulates with a given size, shape, and composition.  This project will study the structure and dynamics of confined, multicomponent suspensions in viscoelastic fluids, using a combination of simulations, coarse-grained theories, and microfluidic experiments.  The central goal of this project is to develop a rational framework to predict how such suspensions segregate in wall-bound flows due to lift forces created by viscoelasticity, which will be used for focusing/separation by shape, size, and stiffness. The postdoc will use large scale numerical simulations and coarse-grained theories to gain insight into how channel geometry and fluid rheology alter the separation efficiency of suspensions of a given size, shape, stiffness, and concentration distribution.  Microfluidic studies include holography and confocal imaging of viscoelastic fluids containing spherical and elongated particles.  These will eventually be complemented by flow experiments using whole blood with platelets and white blood cells. 

Start Date


Postdoc Qualifications

The postdoctoral researcher should have a degree in Chemical Engineering, Mechanical Engineering, Materials Science, or equivalent.  The research requires a strong background in fluid mechanics and rheology.  Experience in microfluidics as well as working knowledge of computational fluid dynamics is desirable.


1. Vivek Narsimhan, Assistant Professor of Chemical Engineering,,
2. Arezoo Ardekani, Professor of Mechanical Engineering,,
1. C. Tai, S. Wang, and V. Narsimhan.  "Cross-stream migration of non-spherical particles in a second-order fluid - theories of particle dynamics in arbitrary quadratic flows".  J. Fluid Mech., 895, pp A6, (2020).  DOI:
2. S. Wang, C. Tai, and V. Narsimhan.  "Dynamics of spheroids in an unbound quadratic flow of a general second-order fluid". Physics of Fluids, 32, 113106,  (2020).  DOI: 
3. Li G, McKinley GH, Ardekani AM. Dynamics of particle migration in channel flow of viscoelastic fluids. J Fluid Mech. 2015;785:486-505. doi: 10.1017/jfm.2015.619
4. Karimi A, Yazdi S, Ardekani AM. Hydrodynamic mechanisms of cell and particle trapping in microfluidics. Biomicrofluidics. 2013;7(2):021501. doi: 10.1063/1.4799787.
5. A.H. Raffiee, S. Dabiri, A.M. Ardekani, "Elasto-inertial migration of deformable capsules in a microchannel", Biomicrofluidics, 11, 064113, 2017