DLD Microfluidic Recirculation for Consistent Particle Concentration

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Solution Overview

Problem

Current deterministic lateral displacement (DLD) methods face challenges in achieving consistent product concentration across multiple donor samples, require large volumes of wash fluid, and risk contamination due to collection of particles below the critical diameter, making it difficult to standardize output concentrations.

Innovation Solution

The method involves recirculating product streams back onto microfluidic devices, using valves and pumps to control concentration by adjusting the ratio of sample to wash fluid, allowing for adjustable and consistent product concentration without additional concentrator devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high concentration factors are achieved using current DLD procedures, then product concentration is improved, but the risk of contamination increases due to collection of particles below critical diameter

Engineering Contradiction:
Improveproduct concentrationVSAvoidcontamination risk
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The invention divides the DLD process into distinct stages: an initial separation phase where sample and wash fluid are processed together, followed by a recirculation phase where collected product is looped back as wash fluid. This segmentation allows optimization of each phase for its specific function, achieving high concentration without contamination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention implements continuous recirculation of the collected product stream back through the DLD device as wash fluid. This continuous action progressively concentrates the target particles while maintaining separation efficiency, allowing the system to achieve high concentration factors without increasing contamination risk.

Inventive Principle:
Principle #20Continuity of useful action

2Productivity

If large volumes of wash fluid are used to process entire sample volume, then processing completeness is improved, but product concentration is reduced

Engineering Contradiction:
Improveprocessing completenessVSAvoidproduct concentration
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

Instead of discarding the wash fluid after a single pass, the invention recovers and recirculates the collected product stream back as wash fluid. This recovering approach allows the same fluid to be used multiple times, progressively concentrating the target particles while maintaining processing completeness.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The recirculation system maintains continuous useful action by constantly looping the collected stream back through the device. Each pass continues to separate and concentrate particles, achieving both processing completeness and high concentration without requiring large volumes of fresh wash fluid.

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If DLD arrays with extra redundancy are used to ensure efficient bumping into narrow collection width, then separation efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidarray redundancy
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention segments the separation process into an initial phase using a standard DLD array followed by a recirculation phase. This segmentation allows the use of a simpler, non-redundant array design while achieving high separation efficiency through the multi-pass recirculation approach rather than through array redundancy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The continuous recirculation of collected product provides ongoing separation action that compensates for the lack of array redundancy. Each pass through the simpler array continues to refine the separation, achieving high manufacturing precision without increasing device complexity.

Inventive Principle:
Principle #20Continuity of useful action

4Stability of the object's composition

If up-front dilution is performed for each sample to standardize output concentration, then consistency across samples is improved, but processing time and complexity increase

Engineering Contradiction:
Improveoutput concentration consistencyVSAvoidprocessing time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The invention implements a dynamic recirculation system where the number of recirculation passes can be adjusted based on the desired concentration factor. This dynamic approach allows standardization of output concentration across different input samples without requiring separate up-front dilution steps for each sample, reducing processing time and complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameter of recirculation count to achieve different concentration factors. By adjusting how many times the collected stream is recirculated, the system can standardize output concentration across samples with different input concentrations, eliminating the need for sample-specific dilution calculations and steps.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables flexible concentration adjustment, reduces wash fluid volume, and maintains processing time while achieving high concentration factors, independent of input concentration, without requiring separate concentrators.

Implementation Method 1

Deterministic lateral displacement (DLD) typically uses two co-flowing liquids, one containing particles (the sample) and one that is a wash/collection fluid (the 'running' or 'wash' fluid). During DLD, particles above the critical diameter of the array are deflected into the wash fluid whereas particles below the critical diameter follow the flow direction of the sample stream.

Methodology Applied
Scientific EffectDeterministic lateral displacement:

Implementation Method 2

This can be accomplished using standard valves, with the recycled product stream being propelled using, for example, pressurized containers, peristaltic pumps, or syringe pumps.

Methodology Applied
Scientific EffectPeristaltic pumping: Peristaltic Pump

Data Source

PatentEP3793737B1Combined purification and concentration by deterministic lateral displacement with recirculation product
Publication Date: 2026.01.14 ZEON CORP
  • EP3793737B1 patent drawingFigure 1A~1G
  • EP3793737B1 patent drawingFigure 2
  • EP3793737B1 patent drawingFigure 3

AI summary

The present invention is directed to microfluidic procedures in which cells or particles are purified with recirculation of product. The present invention is directed to methods of simultaneously purifying and concentrating cells or other particles by performing deterministic lateral displacement on microfluidic devices while recirculating product.