Microfluidic Capillary Stop via Channel Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microfluidic systems face challenges in accurately controlling the flow of liquids across capillary stops, particularly in maintaining a uniform and straight liquid front, which affects time and location precision, and are often costly due to hardware complexity.
Innovation Solution
The device allows two channel sections to move relative to each other to bridge or cancel the capillary stop, enabling uniform liquid flow across large channel cross sections with precise time control by bringing the channel sections into contact, thus maintaining a straight liquid front and laminar flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a capillary stop is formed by a trough-like control channel to temporarily stop liquid, then the liquid can be stopped in time, but the liquid front becomes narrowed and then widened again due to diffusion processes, adversely affecting local resolution
Solution Approach 1:
The channel is divided into two separable channel sections that can be moved relative to each other. This segmentation allows the liquid front to be stopped uniformly across the entire channel cross-section without the narrowing and widening effects that occur in tapered control channels, thereby maintaining local resolution while achieving time control.
Solution Approach 2:
The channel sections are made movable relative to each other, allowing dynamic control of the liquid flow. By moving the channel sections, the capillary stop can be bridged or canceled to start liquid flow uniformly across the entire cross-section, avoiding the diffusion-related resolution loss while maintaining time accuracy.
2Loss of time
If the channel cross section is tapered in the area of the capillary stop to obtain better time control, then time definition is improved, but the liquid front is narrowed and then widened again, significantly adversely affecting local resolution
Solution Approach 1:
Instead of tapering the channel cross-section, the channel is segmented into two separable sections. This allows time control to be achieved through the relative movement of sections rather than through geometric tapering, thereby maintaining a uniform liquid front and preserving local resolution.
Solution Approach 2:
Rather than modifying the channel geometry (tapering) to achieve time control, the invention inverts the approach by keeping the channel cross-section uniform and achieving time control through the relative movement of channel sections. This prevents the liquid front distortion that would otherwise occur.
3Ease of operation
If external triggers such as electrical and/or magnetic fields, surge waves or pressure waves are used to temporarily stop liquid, then liquid transport can be controlled, but hardware complexity and costs increase
Solution Approach 1:
The system uses the liquid's own capillary forces to control its flow and stopping. By moving the channel sections, the capillary stop is bridged or canceled, allowing the liquid to start or stop flow without requiring external triggers such as electrical fields, magnetic fields, surge waves, or pressure waves, thereby reducing hardware complexity.
Solution Approach 2:
The invention replaces complex external trigger systems (electrical, magnetic, acoustic, or pressure-based) with a simple mechanical approach: moving the channel sections relative to each other. This mechanical solution achieves the same liquid transport control with significantly reduced hardware complexity.
4Ease of operation
If selective venting is used to temporarily stop liquid by stopping air displacement in the channel, then liquid flow can be controlled, but hardware cost increases
Solution Approach 1:
The system uses the liquid's own capillary properties to control flow without requiring additional venting hardware. By moving the channel sections, the capillary stop is bridged or canceled, allowing flow control through the liquid's inherent properties rather than through complex venting mechanisms.
Solution Approach 2:
The invention replaces the selective venting mechanism with a simpler mechanical approach: relative movement of channel sections. This eliminates the need for vents and air displacement control hardware, thereby reducing hardware cost while maintaining flow control capability.
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 ensures accurate and uniform liquid flow over the entire channel cross section, enhancing time and location definition, which is crucial for analyses and detection processes, while reducing hardware complexity and costs.
Implementation Method 1
capillary forces act and are decisive especially for operation
Implementation Method 2
bridge or cancel the capillary stop between a first channel section and a second channel section
Data Source
AI summary
A device and a process for manipulation of a liquid, the ability of a liquid to flow from a first channel section in a second channel section being temporarily stopped by means of a capillary stop before it flows from the first channel section into the second channel section. Control which is accurate in time is easily enabled by the two channel sections being moved relative to one another for bridging or cancelling the capillary stop, especially being brought into contact.