Rotatable Microfluidic Device Dissolvable Valve Control

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Solution Overview

Problem

Existing microfluidic devices face challenges in selectively controlling fluid flow due to the complexity and requirements of external triggers for sacrificial valves, such as wax valving and pressure-based mechanisms, which limit the number and simplicity of valves that can be incorporated.

Innovation Solution

A rotatable microfluidic device with a sacrificial valve configuration where actuation of an actuation member causes a fluid spacer to retract, allowing a liquid to contact and dissolve the valve, enabling sequential and selective control of fluid flow without external stimuli, using dissolvable membranes and gas pockets to manage valve opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional sacrificial valves (wax valving, pressure-based mechanisms) are used, then fluid flow control is achieved, but the device complexity and requirement for external triggers increases

Engineering Contradiction:
Improvevalve control simplicityVSAvoidexternal trigger requirements
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The valve system uses self-service through cascading dissolution: the first dissolvable valve opens automatically when liquid reaches it, and this same liquid flow triggers the second valve downstream without requiring external control mechanisms. The system serves itself by using the flowing liquid as both the operational medium and the trigger mechanism.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The flowing liquid acts as an intermediary that transfers the triggering action from one valve to the next. As the liquid passes through the first valve, it carries the activation function to the second valve, enabling sequential operation without direct external intervention at each stage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple sacrificial valves are incorporated, then fluid flow control capability improves, but the manufacturing complexity and number of components increases

Engineering Contradiction:
Improvefluid flow control capabilityVSAvoidnumber of valve components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each dissolvable valve membrane serves multiple functions: it acts as a flow barrier, a trigger mechanism for downstream valves, and a temporary structural element. The liquid itself serves multiple roles as both the operational fluid and the activation trigger, reducing the need for separate control components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the valve function with the fluid flow path by using dissolvable membranes that become part of the liquid stream upon dissolution. This integration reduces the number of discrete components needed, as the valve material itself transitions from solid barrier to dissolved trigger agent.

Inventive Principle:
Principle #5Merging (Combining)

3Extent of automation

If dissolvable membranes are used for valves, then passive control and sequential operation are enabled, but the control over valve opening timing precision may be reduced

Engineering Contradiction:
Improvepassive control capabilityVSAvoidvalve opening timing precision
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The system is pre-configured with dissolvable membranes at specific locations and the liquid is pre-loaded in the reservoir. When the device operates, the liquid naturally flows to and dissolves the first valve, which then triggers the second valve in sequence. This preliminary arrangement enables automatic sequential operation without real-time control intervention.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The dissolution rate and timing are controlled by changing parameters such as membrane material composition, thickness, and surface area, as well as liquid properties like flow rate and chemical composition. These parameter adjustments allow tuning of the sequential activation timing while maintaining passive operation.

Inventive Principle:
Principle #35Parameter changes

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 solution allows for passive control of sequential valve operations, reducing the need for external actuation mechanisms and enabling flexible, sequential release of fluids in bioanalytical assays, while maintaining the strength of physical barriers for fluid management.

Implementation Method 1

allows a liquid come into contact with and dissolve the first valve

Methodology Applied
Scientific EffectDissolution:

Implementation Method 2

the first valve is provided with a fluid spacer provided upstream of the first valve, the fluid spacer separating a dissolvable membrane of the first valve from a liquid

Methodology Applied
Scientific EffectPhysical barrier separation:

Implementation Method 3

Actuation of the actuation member causes a retraction of the fluid spacer and allows the liquid to come into contact with the dissolvable membrane

Methodology Applied
Scientific EffectFluid displacement:

Data Source

PatentEP2994232B1Rotatable microfluidic device with dissolvable release valve and control valve
Publication Date: 2018.05.02 DUBLIN CITY UNIVERSITY
  • EP2994232B1 patent drawingFigure 1A~1B
  • EP2994232B1 patent drawingFigure 1C
  • EP2994232B1 patent drawingFigure 1D

AI summary

Microfluidic devices and in particular microfluidic devices incorporating a cascading valve arrangement for selectively controlling the flow of a fluid within the microfluidic device are described. Specific examples of a microfluidic device comprising a sacrificial valve (210) whose opening is triggered by the opening of a second valve (220), causing a retraction of a fluid spacer (213) thus bringing liquid (214) into contact with the dissolvable valve membrane (210).