Magnetic Levitation Cell Sorting for Portable Label-Free Diagnosis

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Solution Overview

Problem

Existing magnetic levitation technologies are not compatible with microscopy and are not suitable for portable, robust, and inexpensive disease diagnosis and prognosis monitoring platforms for point-of-living applications, particularly in clinical and home settings, lacking the ability to separate and analyze cells without labels.

Innovation Solution

A magnetic levitation-based diagnosis system using a smartphone-integrated imaging device separates cells based on their magnetic susceptibility and intrinsic density, allowing label-free identification and quantification of cell types, such as white and red blood cells, through a microcapillary or microfluidic channel with a magnetic field, enabling high-throughput isolation of circulating tumor cells and other biological moieties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional magnetic levitation setups are used, then separation based on density and magnetic susceptibility is achieved, but the system is not compatible with microscopy and not suitable for portable applications

Engineering Contradiction:
Improvecompatibility with microscopy and portabilityVSAvoidsetup size and complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments the magnetic levitation function into a compact microfluidic chip with integrated magnets, separating it from the imaging function performed by external microscopy equipment. This allows the magnetic separation core to be miniaturized while maintaining compatibility with standard microscopy systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent nests the magnetic levitation components (magnets, microchannel) within a compact housing that can be integrated into or positioned near microscopy equipment. The smartphone is nested within the device housing, providing both imaging and computational capabilities in a portable package.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If label-free cell identification is implemented, then ease of operation and cost are improved, but measurement precision and reliability may be compromised

Engineering Contradiction:
Improvesimplicity of use and costVSAvoidcell identification accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system changes the measurement parameters from optical/chemical labels to physical properties (density and magnetic susceptibility) that inherently differ between cell types. This label-free approach uses fundamental cellular properties rather than added markers, simplifying operation while maintaining precision through multi-parameter measurement.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces complex optical labeling and detection systems with a magnetic field-based separation and imaging approach. This substitution uses magnetic forces and optical imaging of the magnetic field interaction, eliminating the need for fluorescent labels or complex staining protocols while maintaining cell identification accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If high-throughput isolation is achieved, then productivity increases, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvethroughput of cell isolationVSAvoidmanufacturing simplicity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The system uses microfluidic hydraulic principles to achieve high-throughput cell processing. The paramagnetic medium flow through the microchannel enables continuous sample processing, and the magnetic field applied perpendicular to flow direction separates cells based on their magnetic susceptibility, allowing high throughput without complex mechanical moving parts.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the operating parameters by using a flowing paramagnetic medium instead of static separation methods. This enables continuous high-throughput processing while the microfluidic channel design and integrated magnets keep the manufacturing process relatively simple using standard microfabrication techniques.

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

Enables efficient separation and analysis of cells at single-unit resolution, facilitating disease diagnosis and monitoring in various settings, including home and clinical environments, and supports applications like high-throughput isolation of rare CTCs and three-dimensional cell culture.

Implementation Method 1

a magnetic field is applied using the magnet(s) to the sample, such that the application of the magnetic field levitates at least a portion of the population of moieties

Methodology Applied
Scientific EffectMagnetic levitation: Maglev

Implementation Method 2

separates cells based on their magnetic susceptibility and intrinsic density

Methodology Applied
Scientific EffectMagnetic susceptibility difference: Magnetism

Implementation Method 3

different units (for example, white and red blood cells or other moieties) are levitated in a magnetic gradient and separated due to their unique densities

Methodology Applied
Scientific EffectDensity-based separation: Density Gradient

Data Source

PatentEP3356820B1Sorting biological moieties using magnetic levitation
Publication Date: 2026.03.11 THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIV
  • EP3356820B1 patent drawingFigure 1A~2H
  • EP3356820B1 patent drawingFigure 3A~3F
  • EP3356820B1 patent drawingFigure 4A~4E

AI summary

Systems and methods for levitating populations of moieties, cells, or other such units using one or more magnets in a microfluidic environment are provided. These systems and methods may be used to, for example, separate or sort heterogeneous populations of the units from one another, to assembly a multi-unit assembly during the levitating of the units, and to evaluate samples at the point of care in real-time. These systems and methods may also utilize a frame that enables an imaging device, such as a smartphone, to capture the units in real time as they are manipulated in the system.