Microfluidic Valve With Elastic Pressing Member for Reversible Flow Control

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Solution Overview

Problem

Conventional microfluidic devices face challenges in efficiently controlling fluid flow due to limitations in valve operation, including lack of local control, irreversibility, and vulnerability to high temperatures, which hinder automation and integration in diagnostic devices.

Innovation Solution

A microfluidic device with a valve structure featuring a blocking member made of elastic material, a pressing member for linear motion, and a driving unit that reversibly controls the valve's opening and closing by fixing or returning the pressing member to specific positions, allowing for one-touch operation and mechanization of fluid control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a capillary valve using only disc structure is used, then the valve is easy to prepare and use, but local fluid flow control is impossible and the fluid cannot be reused

Engineering Contradiction:
Improveease to prepareVSAvoidlocal fluid flow control
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The valve is divided into multiple independent chambers (first chamber, second chamber, third chamber) with separate control mechanisms. Each chamber can be controlled independently through its own pressing member, enabling local fluid flow control while maintaining the simplicity of the overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The valve incorporates elastic pressing members that can dynamically change position between pressed and unpressed states. This dynamic capability allows the valve to control fluid flow in both directions (forward and reverse), enabling fluid reuse while maintaining ease of preparation.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If a wax-based valve with laser control is used, then local and selective microfluidic control is available, but external energy sources are needed and reversible use is impossible

Engineering Contradiction:
Improvelocal and selective microfluidic controlVSAvoidexternal energy sources
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention replaces the laser-based thermal control mechanism with a mechanical pressing system. Instead of using external laser energy to melt and recystallize wax, the valve uses elastic pressing members that can be mechanically actuated to open or close channels, eliminating the need for external energy sources while maintaining local control capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The elastic pressing members are designed to automatically return to their original position after being pressed, enabling reversible operation without external energy input. The elastic material stores and releases mechanical energy, allowing the valve to perform both opening and closing actions through simple mechanical pressing.

Inventive Principle:
Principle #25Self-service

3Reliability

If a wax-based valve is used, then the valve can block steam flow, but the valve is weak in high temperature and difficult to use for reactions accompanying heat

Engineering Contradiction:
Improvesteam flow blockingVSAvoidhigh temperature resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention changes the material parameter from temperature-sensitive wax to temperature-resistant elastic material. The elastic material maintains its mechanical properties at high temperatures, allowing the valve to block fluid flow reliably even in high-temperature environments such as molecular diagnosis reactions, while still providing effective sealing.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If manual operation of pressing member is required, then the valve can control microfluidic flow, but the user has to manually operate the pressing member to open or close the valve

Engineering Contradiction:
Improveflow control capabilityVSAvoidmanual operation requirement
Core Design Contradiction:
Ease of operationVSExtent of automation

Solution Approach 1:

The elastic pressing members are designed to automatically return to their original position after being pressed, enabling automatic reversal of the valve state without requiring manual intervention. This self-service mechanism allows the valve to perform both opening and closing actions through simple mechanical pressing, reducing the need for complex manual operation while maintaining flow control capability.

Inventive Principle:
Principle #25Self-service

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

Enhances the usability of microfluidic devices by improving valve operability, enabling automation and efficient fluid control with reduced manual intervention and increased robustness against temperature variations.

Implementation Method 1

The blocking member may have a structure made of a material having elasticity, and which opens and closes the flow channel by being pressed and transformed by the pressing member

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3020682B1Microfluidic device and control equipment for microfluidic device
Publication Date: 2019.01.09 UNIST (ULSAN NAT INST OF SCI & TECH)
  • EP3020682B1 patent drawingFigure 1
  • EP3020682B1 patent drawingFigure 2
  • EP3020682B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is a microfluidic device to more easily and mechanical ly operate a valve for controlling a fluid flow, which comprises: a platform having a plurality of chambers; at least one flow channel which connects between the chambers; and a valve which opens or closes the flow channel, wherein the valve includes a blocking member which selectively blocks the flow channel and a pressing member installed in the blocking member to move the blocking member, and the pressing member has a structure which presses and moves the blocking member by the linear reciprocat ing mot ion in the same direction as the direction of an external force, and the valve further includes a driving unit which reversibly controls the opening and closing of the flow channel caused by the blocking member by fixing the pressing member to the position of the moved pressing member or returning to the original position.