Inertia and scaling in deterministic lateral displacement.

Area of Science:

• Microfluidics
• Biophysics
• Chemical Engineering

Background:

• Microfluidic systems require high-resolution, sensitive, and high-throughput separation techniques.
• Deterministic lateral displacement (DLD) is a continuous separation method utilizing obstacle arrays.
• Force-driven DLD (f-DLD) typically models size-based separation via particle-obstacle collisions.

Purpose of the Study:

• To investigate the underlying principles of force-driven deterministic lateral displacement (f-DLD).
• To explore the influence of inertia on particle separation in f-DLD.
• To establish a scalable model for translating macroscopic f-DLD findings to microfluidic devices.

Main Methods:

• Macroscopic modeling of particle transport through obstacle arrays.
• Analysis of particle-obstacle collision dynamics.
• Development of a scaling law to relate macroscopic and microfluidic DLD behavior.

Main Results:

• f-DLD is confirmed as a predominantly size-based separation method at low Reynolds numbers.
• Inertia effects were shown to enable separation of same-sized particles with differing densities.
• A universal scaling curve was derived, allowing direct conversion of macroscopic results to microfluidic settings.

Conclusions:

• f-DLD offers size-based separation, with inertia providing additional capabilities for density-based separation.
• The developed scaling method facilitates the design and optimization of microfluidic separation devices.
• This research enhances the potential of DLD for high-throughput particle analysis in microfluidics.