Microfluidic Control Valve Structure for Leak-Free Sample Flow
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Solution Overview
Problem
Existing microfluidic control valves suffer from liquid leakage due to shifting valve cores when closed, leading to inefficient sample liquid control in microfluidic systems.
Innovation Solution
A control valve structure featuring a cover plate layer, channel layers, adhesive layers, valve cores, and elastic films, where the valve core's movement is defined by corresponding limiting holes and through holes, ensuring the elastic film seals the holes to prevent leakage by maintaining the valve core's position without shifting, thus forming a stable sample liquid flow channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional control valve structure is used, then the device complexity is reduced, but liquid leakage occurs due to valve core shifting
Solution Approach 1:
The valve structure is divided into multiple functional layers: a first channel layer with second limiting holes, a second channel layer with liquid outlet channels, and a cover plate layer with first limiting holes. This segmentation allows each layer to perform its specific function (flow control, outlet regulation, and positioning) independently, preventing valve core shifting while maintaining manageable complexity through modular design
Solution Approach 2:
The valve core is nested within the first limiting hole of the cover plate layer, which itself is positioned over the second limiting hole of the first channel layer. This nested arrangement creates a hierarchical positioning system where the cover plate layer's first limiting hole constrains the valve core movement, preventing shifting while allowing the valve core to still seal against the second limiting hole effectively
2Reliability
If the valve core is allowed to move freely for sealing, then the ease of operation is improved, but the valve core shifts position causing leakage
Solution Approach 1:
The cover plate layer provides localized positioning constraints through the first limiting hole, which restricts the valve core movement only in the lateral direction while allowing vertical movement for sealing. This localized quality approach maintains sealing integrity through precise positional control without restricting the valve core's ability to move up and down for opening and closing operations
Solution Approach 2:
The first limiting hole acts as an intermediary element between the valve core and the external environment. It provides a guided pathway that allows the valve core to move vertically for operation while preventing lateral shifting, thus mediating between the need for operational freedom and the need for positional stability to prevent leakage
3Reliability
If multiple limiting holes and layers are added to prevent shifting, then the reliability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The cover plate layer with pre-formed first limiting holes is positioned and fixed to the first channel layer before final assembly. This preliminary action establishes the positioning reference early in the manufacturing process, ensuring that the second limiting holes and first limiting holes are properly aligned before components are permanently joined, thereby reducing the overall manufacturing precision requirements
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 solution effectively reduces liquid leakage by ensuring the valve core remains in place during closure, maintaining the integrity of the sample liquid flow channel and enhancing the control of sample liquid flow in microfluidic systems.
Implementation Method 1
at least one elastic film on a side, close to the at least one second limiting hole, of the at least one valve core, respectively; wherein when the valve core is at least partially in the first limiting hole, the first limiting hole is sealed by the elastic film
Data Source
AI summary
A control valve structure, a using method thereof, a microfluidic chip, and a nucleic acid extraction device. The control valve structure includes: a cover plate layer, a first channel layer, a first adhesive layer, a second channel layer, at least one valve core, and at least one elastic film. When the valve core is embedded in the first limiting hole, the elastic film seals the first limiting hole, and the second limiting hole, the first through hole and the liquid outlet channel form a sample liquid flow channel; and when the valve core is embedded in the second limiting hole, the elastic film seals the second limiting hole so as to block the sample liquid flow channel.