Microfluidic Device With Magnetizable Layer For Particle Sorting
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Solution Overview
Problem
Current magnetic cell separation techniques using magnetic fields struggle to efficiently isolate magnetically labeled particles from fluid samples due to limitations in generating high enough magnetic field gradients within microfluidic devices, leading to incomplete separation and potential clogging issues.
Innovation Solution
The development of microfluidic devices that utilize high magnetic field gradients by incorporating a magnetizable layer with high and low magnetic permeability materials, creating a fringing flux field that deflects magnetic particles within the microfluidic channel, allowing for efficient sorting and isolation of target analytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional magnetic fields are used for particle separation, then the separation process can be implemented, but the magnetic field gradient is insufficient leading to incomplete separation and potential clogging
Solution Approach 1:
The magnetizable layer is designed with spatially varying magnetic permeability, creating regions of high and low permeability that generate localized high gradient magnetic fields at specific positions within the microfluidic channel. This local quality variation enables strong magnetic forces to be concentrated at the separation interface, improving particle separation efficiency while preventing clogging through controlled field distribution.
Solution Approach 2:
The invention changes the magnetic permeability parameter of the layer material from uniform to non-uniform distribution. By using materials with different magnetic permeability values in different regions of the same layer, the system generates high gradient magnetic fields that enhance the magnetic force acting on particles, thereby improving separation efficiency and reducing clogging risks.
2Manufacturing precision
If high magnetic field gradients are generated using conventional methods, then particle separation can be improved, but the device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
The invention merges the magnetic field generation function and the structural support function into a single integrated magnetizable layer. This layer simultaneously provides mechanical support for the microfluidic device and generates the high gradient magnetic field through its non-uniform magnetic permeability distribution, eliminating the need for separate complex magnetic field generation components.
Solution Approach 2:
The magnetizable layer serves multiple functions: it acts as a structural component of the device, provides magnetic field generation, and creates the high gradient regions necessary for particle separation. This multi-functionality reduces the overall device complexity while achieving effective particle separation.
3Manufacturing precision
If longer microfluidic channels are used to improve separation, then particle isolation can be enhanced, but the device length and processing time increase
Solution Approach 1:
By changing the magnetic permeability parameter distribution in the layer, the invention creates high gradient magnetic fields that generate stronger magnetic forces on particles. This allows separation to be achieved in shorter channel lengths compared to conventional uniform field configurations, reducing both device length and processing time while maintaining high separation efficiency.
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 effective sorting of magnetic particles and analytes with high efficiency, even at high flow rates and shorter channel lengths, while minimizing clogging risks by directing particles to specific collection paths, thus improving the separation process.
Implementation Method 1
The magnetizable layer is configured to induce a gradient in the magnetic field of at least one of the magnets, the gradient being at least 10³ Gauss/cm
Implementation Method 2
KR 2012/0026959 A, against which claim 1 is delimited, describes an apparatus for separating fine particles using magnetophoresis
Implementation Method 3
The high magnetic permeability region provides a preferred path for flux lines emanating from the one or more magnets, such that the magnetic field lines extend over the low magnetic permeability region to establish a fringing flux field with a high field gradient
Implementation Method 4
Typically, magnetic particles are selectively attached to one or more desired cells using antibodies that bind to the cell surface
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
This disclosure describes microfluidic devices that include one or more magnets, each magnet being operable to emit a magnetic field; and a magnetizable layer adjacent to the one or more magnets, in which the magnetizable layer is configured to induce a gradient in the magnetic field of at least one of the magnets. For example, the gradient can be at least 103T/m at a position that is at least 20 ?m away from a surface of the magnetizable layer. The magnetizable layer includes a first high magnetic permeability material and a low magnetic permeability material arranged adjacent to the high magnetic permeability material. The devices also include a microfluidic channel arranged on a surface of the magnetizable layer, wherein a central longitudinal axis of the microfluidic channel is arranged at an angle to or laterally offset from an interface between the high magnetic permeability material and the low magnetic permeability material.