Membrane Microfluidic Valve with Nested Actuation

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Solution Overview

Problem

The complexity and high manufacturing costs of controlled microfluidic valves, particularly in integrating microchannels and mobile members within the valve body, lead to reliability issues and alignment difficulties during production.

Innovation Solution

A membrane microfluidic valve comprising a first and second structural layer bonded together, with a movable membrane between them, responsive to actuation stimuli, such as magnetic fields, to control fluid communication between microfluidic conduits, allowing for a simple and cost-effective integration within microfluidic devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex micromachining operations or multiple bonded substrates are used to integrate microchannels and mobile members, then the valve functionality is achieved, but the manufacturing complexity and cost increase significantly

Engineering Contradiction:

Improvevalve functionalityVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The valve body is segmented into a housing and a separate movable member (membrane/disc assembly). The microchannels are formed in the housing while the movable member is created separately, allowing independent fabrication and simplification of manufacturing processes for each component.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The movable member is nested within the housing structure, with the membrane or disc positioned inside the valve body and the actuator integrated within the same assembly. This nested arrangement consolidates multiple components into a compact integrated unit that simplifies manufacturing.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If multiple substrates are bonded together to form the valve structure, then the microfluidic circuit is created, but alignment difficulties and manufacturing challenges arise

Engineering Contradiction:

Improvemicrofluidic circuit integrityVSAvoidsubstrate alignment

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The microchannel formation and movable member integration are merged into a single manufacturing process using soft lithography. The PDMS housing and movable members are molded simultaneously or in sequence without requiring separate bonding steps, eliminating alignment issues between multiple substrates.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The manufacturing approach changes from rigid substrate bonding to flexible PDMS molding. By using elastomeric materials and replica molding techniques, the process transitions from precision alignment requirements to a more tolerant molding process that achieves circuit integrity without substrate bonding challenges.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If dedicated actuators are added to create controlled microfluidic valves, then the valve control capability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improvevalve control capabilityVSAvoidactuator integration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The movable member is designed to be actuated by pressure differential alone, using the fluid pressure itself to open or close the valve. This self-actuating mechanism eliminates the need for external dedicated actuators, reducing device complexity while maintaining control capability through pressure-responsive operation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Complex mechanical actuator systems are replaced with a simplified pressure-driven mechanical response. The valve uses the inherent pressure differential in the fluid system to actuate the movable member, substituting complex actuator mechanisms with a direct pressure-to-motion conversion that reduces overall device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 provides a reliable, easily integratable, and cost-effective microfluidic valve with a satisfactory fluidic seal and modest actuation forces, simplifying the production process and eliminating alignment challenges.

Implementation Method 1

responsive to actuation stimuli, such as magnetic fields

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentUS10197189B2Membrane microfluidic valve and process for manufacturing a membrane microfluidic valve

Publication Date: 2019.02.05 STMICROELECTRONICS INT NV

AI summary

A microfluidic valve includes: a first structural layer and a second structural layer; a microfluidic circuit having a first microfluidic conduit and a second microfluidic conduit, which are defined in a superficial portion of the first structural layer, are adjacent, and are separated by a wall; a membrane set between the first structural layer and the second structural layer and delimiting the microfluidic circuit on one side; and a recess containing a gaseous fluid in the second structural layer. The membrane is movable in response to an actuation stimulus between a closed position, in which the first and second microfluidic conduits are fluidly decoupled, and an open position, in which the membrane is at least in part retracted into the recess and the first and second microfluidic conduits are fluidly coupled by means of a fluidic passage defined between the wall and the membrane.