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A Microfluidic-based Hydrodynamic Trap for Single Particles
Published on: January 21, 2011
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Hydrodynamic collision between a microswimmer and a passive particle in a micro-channel.
Ahana Purushothaman1, Sumesh P Thampi
1Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India. sumesh@iitm.ac.in.
Soft Matter
|March 1, 2021
Summary
Microswimmers colliding with passive particles exhibit asymmetric hydrodynamic interactions. This study reveals how passive particles are displaced, offering potential for microfluidic particle separation and deposition applications.
Area of Science:
- Fluid dynamics
- Microfluidics
- Biophysics
Background:
- Microswimmers interact with passive particles in confined environments like the reproductive tract and microfluidic channels.
- These interactions are governed by complex, three-way hydrodynamic forces involving the microswimmer, passive particle, and channel walls.
Purpose of the Study:
- To investigate the hydrodynamic collision dynamics between a model microswimmer and a passive particle.
- To analyze the resulting trajectories and displacements under confinement.
Main Methods:
- Point particle approach.
- Analytical calculations using the method of reflections.
- Lattice Boltzmann numerical simulations.
Main Results:
- Hydrodynamic collisions are asymmetric; microswimmer trajectories are temporarily altered.
- Passive particles exhibit a three-stage displacement, with net movement towards or away from walls.
- Particle paths vary from triangular in bulk to loop-like in confinement, driven by swimmer-generated velocity fields.
Conclusions:
- The net displacement of passive particles can be harnessed for applications.
- Potential applications include size separation of colloidal particles and controlled particle deposition within microchannels.
