Methods and devices for separating particles in a liquid flow
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Solution Overview
Problem
Conventional particle separation methods in fluidic microsystems face limitations in reliability, complexity, and efficiency, particularly in separating particles with similar dielectric properties and biological cells, due to issues like undesired cell components causing clogging and interference with measurements.
Innovation Solution
A method combining dielectrophoretic and electrophoretic forces to guide particles into specific flow paths within a fluidic microsystem, using a combination of focusing and deflecting potentials generated by high-frequency electrical fields, allowing for precise separation of particles based on their geometric, electrical, and magnetic properties, without the need for separation gels or complex channel designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dielectrophoretic separation is used to separate particles with different dielectric properties, then particles can be separated based on their permittivity, but the reliability of separation is limited for particles with similar permittivities and the channel design becomes complex
Solution Approach 1:
The patent combines dielectrophoresis and electrophoresis into a single separation system. The dielectrophoretic component separates particles based on dielectric properties while the electrophoretic component provides additional separation based on charge-to-size ratio, enabling reliable separation of particles with similar permittivities without requiring complex channel geometries
Solution Approach 2:
The patent utilizes the different responses of particles to combined dielectrophoretic and electrophoretic fields by adjusting field parameters such as frequency, voltage amplitude, and flow rate. This allows optimization of separation conditions for different particle types without modifying channel structure
2Measurement precision
If conventional dielectrophoretic separation is used, then particles can be separated by dielectric properties, but undesired cell components cause accumulations and channel constrictions leading to system failure
Solution Approach 1:
The patent applies different field conditions in different regions of the channel. By creating localized electrophoretic fields that act on charged cell components, the system selectively manipulates unwanted particles (such as cell debris and contaminants) to prevent their accumulation in critical channel regions, thereby maintaining system reliability
3Ease of manufacture
If electrophoretic separation is used to separate molecules by molecular weight and charge, then separation can be achieved without separation gels, but a separate microsystem must be provided for each separation task and the process takes great amount of time
Solution Approach 1:
The patent creates a universal microsystem that can perform multiple separation tasks by adjusting electrical field parameters. The same device structure can separate different particle types (cells, proteins, DNA) and molecular weights by modifying voltage, frequency, and flow rate, eliminating the need for separate customized microsystems for each application
Solution Approach 2:
The patent implements continuous flow separation where particles are continuously separated while flowing through the channel under the action of combined dielectrophoretic and electrophoretic fields. This eliminates the need for batch processing and stationary gels, enabling high-throughput separation with rapid particle analysis
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 enhances the reliability and sharpness of particle separation, increases throughput, and avoids clogging, enabling effective separation of diverse particle types, including biological cells, by utilizing adjustable electrical and magnetic forces to direct particles into distinct flow paths.
Implementation Method 1
A field barrier extending transversely over channel 30' is generated with electrode arrangement 40' by subjecting it to high-frequency electrical fields
Implementation Method 2
Electrodes 41', 42', are arranged on the ends of channel 30' formed with alternating broad and narrow sections, which electrodes form an electrophoretic field in channel 30' when subjected to a direct voltage
Data Source
AI summary
Methods and devices for the separation of particles (20, 21, 22) in a compartment (30) of a fluidic microsystem (100) are described, in which the movement of a liquid (10) in which particles (20, 21, 22) are suspended with a predetermined direction of flow through the compartment (30), and the generation of a deflecting potential in which at least a part of the particles (20, 21, 22) is moved relative to the liquid in a direction of deflection are envisaged, whereby further at least one focusing potential is generated, so that at least a part of the particles is moved opposite to the direction of deflection relative to the liquid by dielectrophoresis under the effect of high-frequency electrical fields, and guiding of particles with different electrical, magnetic or geometric properties into different flow areas (11, 12) in the liquid takes place.