Microfluidic Plate Venting Structure for Pressure Management

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Solution Overview

Problem

Existing microfluidic plates often fail to fill microfluidic networks satisfactorily with dispensed liquids or gels due to inadequate capillary pressure barriers, leading to potential experiment failures and incorrect fluid interactions.

Innovation Solution

The microfluidic plate design incorporates a support structure with a non-circular opening and a venting mechanism to decouple dispensing pressure from the microfluidic network, allowing fluid communication between the inlet chamber and the environment, which prevents pressure buildup and ensures controlled filling by capillary forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a capillary pressure barrier is used to control fluid advancement in the microfluidic network, then the fluid filling is controlled and patterned, but pressure buildup may occur in the inlet chamber during dispensing

Engineering Contradiction:
Improvefluid filling controlVSAvoidpressure buildup
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The inlet chamber is segmented into two functional zones: a dispensing zone for receiving fluid and a microfluidic network zone for controlled distribution. The support structure with its opening and vent creates a spatial separation that allows pressure management independent of the capillary pressure barrier function, resolving the contradiction between controlled filling and pressure buildup.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support structure with its opening acts as an intermediary element between the inlet chamber and the external environment. This intermediary provides a dedicated pressure relief pathway that does not interfere with the capillary pressure barrier's ability to control fluid advancement into the microfluidic network channels.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the dispensing end is positioned close to the inlet chamber bottom surface, then dispensing precision is improved, but the capillary pressure barrier may be breached due to direct pressure transmission

Engineering Contradiction:
Improvedispensing precisionVSAvoidcapillary pressure barrier integrity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The pressure management function is extracted from the dispensing process itself. The support structure with its opening removes excess pressure from the inlet chamber before it can be transmitted to the capillary pressure barrier, allowing the dispensing end to be positioned close to the bottom surface for precision without compromising barrier integrity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The support structure provides beforehand cushioning by creating a pressure relief pathway in advance. This prevents pressure buildup that would otherwise occur during normal dispensing operations, protecting the capillary pressure barrier from breaching while allowing precise dispensing positioning.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Quantity of substance

If the inlet chamber is sealed during dispensing, then fluid containment is improved, but pressure builds up and may cause incorrect fluid interactions

Engineering Contradiction:
Improvefluid containmentVSAvoidfluid interaction integrity
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The inlet chamber has different local qualities: a sealed region for fluid containment and a vented region through the support structure opening for pressure management. This local differentiation allows the chamber to simultaneously maintain fluid containment while preventing pressure buildup that could cause incorrect fluid interactions in the microfluidic network.

Inventive Principle:
Principle #3Local quality

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 design enhances the precision and reliability of fluid dispensing, preventing capillary pressure barrier breaching and ensuring that microfluidic networks are filled correctly, maintaining the integrity of experiments involving fluid interactions and reactions.

Implementation Method 1

The capillary pressure barrier is responsible for stopping, controlling advancement or shaping the liquid-air meniscus. The pressure drop over a liquid air interface or meniscus is determined by its two principle radii of curvature as described by the Young-Laplace equation

Methodology Applied
Scientific EffectCapillary pressure: Capillary Pressure

Implementation Method 2

The pressure drop over a liquid air interface or meniscus is determined by its two principle radii of curvature as described by the Young-Laplace equation: Where ΔP is the pressure drop over the meniscus, γ the liquid-air surface tension

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 3

a second empty space is formed, which second empty space extends from the second plane into the inlet chamber and is located outside the first empty space, wherein the second empty space forms a vent to allow fluid communication between the inlet chamber and the surrounding environment

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Data Source

PatentEP3302800B1Microfluidic plate
Publication Date: 2019.08.14 MIMETAS BV
  • EP3302800B1 patent drawingFigure 1
  • EP3302800B1 patent drawingFigure 2
  • EP3302800B1 patent drawingFigure 3

AI summary

Microfluidic plate comprising a plurality of microfluidic networks and inlets providing access to the microfluidic networks, wherein each microfluidic network comprises a capillary pressure barrier and extends through a first plane, each inlet is formed by an inlet chamber having a bottom surface, a support structure is provided above each inlet, which support structure defines an opening and comprises at least one support member positioned at the opening such that a circle can be defined in a second plane extending parallel to the first plane, which circle has the largest possible diameter while being completely located within the opening and in contact with the at least one support member, and the support structure is configured such that a first empty space is formed, which first empty space extends from the second plane towards the inlet chamber and has the form of a right circular cone or a truncated right circle cone, wherein the circle forms a base plane of the right circular cone or the truncated right circle cone.