Critical particle size for fractionation by deterministic lateral displacement

Area of Science:

• Biophysics
• Microfluidics
• Particle Science

Background:

• Deterministic lateral displacement (DLD) offers high-resolution particle fractionation.
• Previous DLD studies demonstrated particle separation in micropost arrays.

Purpose of the Study:

• To develop a model predicting critical particle size for DLD fractionation.
• To investigate the influence of micropost geometry and fluid drive on fractionation.

Main Methods:

• Modeling particle fractionation based on micropost geometry (gap, offset).
• Analysis of hydrodynamic and electroosmotic fluid flow effects.
• Experimental validation using particles ranging from 2.3 to 22 micrometers.

Main Results:

• The critical particle diameter for fractionation is significantly smaller than the gap between microposts.
• Micropost geometry (gap size, row offset) directly impacts critical particle size.
• Fluid drive method (hydrodynamic vs. electroosmotic) influences fractionation efficiency.

Conclusions:

• The developed model accurately predicts critical particle size for DLD fractionation.
• The model's findings are crucial for designing efficient microfluidic devices for particle separation.
• Understanding these parameters prevents clogging and enhances separation resolution.