Liquid Barrier Microwell Formation for Dense Microfluidic Arrays

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Solution Overview

Problem

Current microwell plates face challenges in miniaturization due to solid walls occupying significant surface area, difficulty in accurately adding liquids to small wells, limited flexibility, and compatibility issues with biological and chemical materials, while alternative methods like ink jet printing require sophisticated equipment and have inefficiencies in space filling and sample preparation.

Innovation Solution

A method to create microfluidic arrangements by forming sub-bodies of a liquid on a substrate without mechanical or chemical structures, using a denser second liquid to isolate sub-bodies and allow for flexible, high-resolution, and cost-effective formation of extremely small sub-bodies with non-circular shapes, enabling efficient liquid addition and sample preparation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If microwell plates are miniaturized to increase the number of wells per plate, then the quantity of substance (number of wells) is improved, but the area of stationary object (surface area occupied by solid walls) increases significantly

Engineering Contradiction:
Improvenumber of wellsVSAvoidsurface area occupied by solid walls
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The patent removes the solid walls that traditionally define microwell structures and replaces them with liquid barriers. This extraction of the solid structural element eliminates the surface area consumption by walls while maintaining well separation functionality through immiscible liquid interfaces.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses hydraulic principles by employing immiscible liquids as separation barriers instead of solid walls. The liquid-liquid interface creates effective well separation without requiring physical structures, allowing dense packing of wells while maintaining access to the well bottom for liquid addition.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Quantity of substance

If the well size is reduced to increase density, then the quantity of substance (number of wells) is improved, but the ease of operation (difficulty of adding liquids accurately) deteriorates

Engineering Contradiction:
Improvenumber of wellsVSAvoidease of adding liquids to wells
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

By removing the solid walls that create meniscus interference, the patent eliminates the primary obstacle to accurate liquid addition. The liquid barrier approach allows tips to reach the well bottom without contact-induced meniscus formation, enabling reliable liquid delivery even to extremely small wells.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If solid walls are used to define wells, then the manufacturing precision (structural definition) is improved, but the adaptability (flexibility in well configuration) deteriorates

Engineering Contradiction:
Improvestructural definition of wellsVSAvoidflexibility in well configuration
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent transitions from static solid wall structures to dynamic liquid barriers that can be easily manipulated and reconfigured. The liquid separation method allows for flexible well formation, merging, and reconfiguration without requiring complex manufacturing processes or permanent structural changes.

Inventive Principle:
Principle #15Dynamics

4Strength

If traditional microwell plate materials are used to ensure structural integrity, then the strength (structural stability) is improved, but the object-affected harmful factors (biological and chemical compatibility issues) increase

Engineering Contradiction:
Improvestructural stabilityVSAvoidbiological and chemical compatibility
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material state from solid to liquid for the well-defining barriers. This parameter change allows the use of immiscible liquids with favorable biological and chemical properties, eliminating the leaching and reactivity issues associated with solid materials like PDMS while maintaining effective well separation.

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 allows for the creation of densely packed, high-efficiency microfluidic arrangements with minimal surface area usage, improved liquid handling, and enhanced biological compatibility, reducing the need for complex equipment and increasing cell survival rates.

Implementation Method 1

The second liquid is denser than the first liquid

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Data Source

PatentEP3755462B1Method for manufacturing a microfluidic arrangement
Publication Date: 2024.04.03 OXFORD UNIVERSITY INNOVATION LTD
  • EP3755462B1 patent drawingFigure 1~3
  • EP3755462B1 patent drawingFigure 4~5
  • EP3755462B1 patent drawingFigure 6~7

AI summary

Methods and apparatus for manufacturing a microfluidic arrangement are disclosed. In one arrangement, a continuous body of a first liquid is provided in direct contact with a first substrate. A second liquid covers the first liquid. A separation fluid, immiscible with the first liquid, is propelled through at least the first liquid and into contact with the first substrate along all of a selected path on the surface of the first substrate. First liquid that was initially in contact with all of the selected path is displaced away from the selected path. The first liquid is divided to form sub-bodies of first liquid that are separated from each other. For each of one or more of the sub-bodies, a sub-body footprint represents an area of contact between the sub-body and the first substrate, and all of a boundary of the sub-body footprint is in contact with a closed loop of the selected path surrounding the sub-body footprint.