Negative Angle DLD Array for Multi-Range Particle Separation

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Solution Overview

Problem

Current particle separation technologies, such as deterministic lateral displacement (DLD) arrays, are limited to binary sorting and struggle to efficiently separate particles into three or more size ranges with reduced diffusion and without the need for multiple stages.

Innovation Solution

A negative angle DLD array with pillars arranged in a specific pattern, where rows repeat every N rows with a shift of M columns, where N and M are relatively coprime and N is greater than 1, is used in a microfluidic device to separate particles into three or more size ranges by altering the trajectory of particles based on their size, utilizing a condenser for focusing and additional condenser for collection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional DLD arrays are used for particle separation, then binary sorting is achieved, but the ability to separate particles into three or more size ranges is limited

Engineering Contradiction:

Improveparticle size range separation capabilityVSAvoidarray structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The DLD array is segmented into multiple distinct regions, each with different pillar spacing configurations. The first region has a first pillar spacing designed for separating larger particles, while the second region has a second pillar spacing for separating smaller particles. This segmentation allows a single array to perform multi-range particle size separation that would otherwise require multiple separate devices.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from binary sorting to multi-range sorting by adding a dimensional aspect to the separation capability. By varying the pillar spacing in different regions of the array, the system creates multiple separation thresholds within a single device structure, effectively adding a 'region' dimension to the traditional single-threshold DLD approach.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If multiple stages of DLD arrays are used to separate particles into three or more size ranges, then separation capability is improved, but device complexity and diffusion increase

Engineering Contradiction:

Improvemulti-size-range separation capabilityVSAvoidnumber of separation stages

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple separation functions that would traditionally require separate DLD array stages are merged into a single integrated array structure. The first and second regions with different pillar spacings are combined in one continuous array, allowing particles to experience multiple separation thresholds in a single pass through the device, eliminating the need for multiple sequential stages.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single DLD array is designed to perform multiple separation functions simultaneously by incorporating regions with different pillar spacings. This universal structure can separate particles across multiple size ranges in one device, rather than requiring specialized single-function arrays for each size range.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If particles are separated through multiple stages, then size sorting is improved, but diffusion of particles increases

Engineering Contradiction:

Improveparticle size sorting precisionVSAvoidparticle diffusion

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The particle stream is focused into a narrow trajectory before entering the DLD array using a focusing channel. This preliminary focusing action ensures that particles enter the separation regions in a concentrated stream, minimizing lateral diffusion during the separation process and maintaining precise size-based sorting across multiple regions.

Inventive Principle:

Principle #10Preliminary action

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 efficient separation of particles into distinct size ranges with reduced contamination and diffusion, allowing for precise collection of particles in specific size ranges, enhancing the capability of microfluidic devices for particle analysis and purification.

Implementation Method 1

Instead of the condenser, hydrodynamic focusing may be provided to focus the fluid

Methodology Applied

Scientific EffectHydrodynamic focusing:

Implementation Method 2

A negative deterministic lateral array in a microfluidic device to separate particles into three or more ranges of particle sizes

Methodology Applied

Scientific EffectDeterministic lateral displacement:

Data Source

PatentUS11565262B2Continous band-pass filter size separation using a negative angle DLD array

Publication Date: 2023.01.31 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A microfluidic device comprising a channel within a substrate and a condenser or a hydrodynamic focusing chamber along the channel, configured to focus a fluid containing particles of a plurality of sizes. A negative angle deterministic lateral displacement (DLD) array is configured to receive the focused fluid and separate the particles in the focused fluid into three sizes ranges. The negative angle DLD array comprises a plurality of rows of pillars, wherein the rows of pillars are positioned to repeat a pattern every N rows with a shift of M columns, N and M are relatively coprime, and N is greater than 1.