Microfluidic Device Coupling Pressurized and Capillary Flow Zones
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microfluidic devices face challenges in effectively linking two microfluidic flow zones of different natures while preventing the introduction of air bubbles, which can affect analysis performance and results, especially when transferring liquids from a pressurized zone to a capillary zone.
Innovation Solution
A microfluidic device with a chamber that facilitates the transfer of liquid between an upstream pressurized circuit and a downstream capillary circuit by using a vent to evacuate air, combined with hydrophilic channels for spontaneous capillary flow, ensuring that air bubbles are prevented from entering the downstream zone, allowing efficient liquid transfer without bubble interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a microfluidic device connects two pressurized flow zones, then liquid transfer is efficient, but it cannot transfer liquid from a pressurized circuit to a capillary circuit with different flow modes
Solution Approach 1:
The patent introduces an intermediate chamber between the pressurized upstream circuit and the capillary downstream circuit. This intermediate chamber acts as a mediator that receives pressurized liquid and allows it to transition to capillary flow mode, enabling compatibility between different flow modes while preventing air bubbles from entering the capillary circuit.
Solution Approach 2:
The microfluidic device is segmented into distinct functional zones: a pressurized upstream circuit, an intermediate chamber with specific geometric features, and a capillary downstream circuit. This segmentation allows each zone to operate in its optimal flow mode while the intermediate structure facilitates smooth transition and bubble removal.
2Reliability
If air bubble removal techniques are used (such as air pillars or porous materials), then bubbles are eliminated, but liquid evaporation increases
Solution Approach 1:
Instead of using traditional air pillars or porous materials that create large surface areas for bubble removal (which cause evaporation), the patent inverts the approach by using a closed intermediate chamber with controlled geometric features that remove bubbles through pressure differential and gravitational settling, minimizing liquid exposure to air and thus reducing evaporation.
3Reliability
If a complex chamber structure modification is used to control the filling front, then bubble formation is prevented, but device complexity increases
Solution Approach 1:
The patent controls the filling front by changing physical parameters such as pressure differential, channel dimensions, and surface tension effects rather than using complex structural modifications. The intermediate chamber has specific geometric parameters that naturally guide the liquid front and prevent bubble entrapment during filling.
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
The device enables effective coupling of microfluidic circuits with different flow modes, preventing air bubbles and ensuring complete liquid transfer while minimizing waste, thereby enhancing the reliability and accuracy of microfluidic analyses.
Implementation Method 1
the microfluidic chamber comprises a vent configured to evacuate the air contained in the liquid flowing in said microfluidic chamber
Implementation Method 2
the upstream and downstream microfluidic circuits being connected to a microfluidic chamber extending between an inlet channel, forming one end of the upstream microfluidic circuit and an evacuation channel, forming one end of the downstream microfluidic circuit
Implementation Method 3
the evacuation channel has a section, in a plane perpendicular to the flow direction of the liquid, sized to allow evacuation of liquid from the microfluidic chamber through said evacuation channel by spontaneous capillary flow
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a microfluidic device comprising a first microfluidic circuit referred to as upstream (11) and a second microfluidic circuit referred to as downstream (13), the upstream and downstream microfluidic circuits (11, 13) being connected to a microfluidic chamber (3) extending between an inlet channel (51), forming one end of the upstream microfluidic circuit (11) and an outlet channel (71), forming one end of the downstream microfluidic circuit (13), and in that: - the microfluidic chamber (3) has a volume adapted to form a retention of a liquid flowing between the upstream microfluidic circuit (11) and the downstream microfluidic circuit (13), - the outlet channel has a cross-section, in a plane perpendicular to the direction of flow of the liquid, dimensioned to allow evacuation of the liquid from the microfluidic chamber (3) through said outlet channel by spontaneous capillary flow,and - the microfluidic chamber (3) includes a vent (9) configured to evacuate the air contained in the liquid flowing into said microfluidic chamber (3) from the upstream microfluidic circuit (11).