Microfluidic Device Suction Member Capillary Emulsion Generation

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Solution Overview

Problem

Conventional microfluidic devices for generating monodisperse emulsions are complex to connect with syringe pumps, especially when using negative pressure, which is often avoided due to the need for simultaneous pressure application and additional pump connection requirements.

Innovation Solution

A microfluidic device equipped with a suction member made from shape memory polymer, which provides a predetermined suction force to drive the movement of liquids and generate monodisperse emulsions, featuring capillary inlets and channels with affinity for liquids, and a modular suction member that transforms between states to facilitate easy assembly and operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional microfluidic devices use syringe pumps to drive liquids through narrow tubes, then monodisperse emulsions can be generated, but the device complexity and connection requirements increase significantly

Engineering Contradiction:

Improveemulsion generation capabilityVSAvoidconnection complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the syringe pump system from the microfluidic device by utilizing capillary action as the driving mechanism. The narrow tubes connecting syringe pumps are removed, and liquids are driven through the microfluidic channels using capillary forces generated by the channel geometry and surface properties, thereby simplifying the device structure and reducing connection complexity while maintaining emulsion generation capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The microfluidic device achieves self-driven liquid flow through capillary action without requiring external pumping equipment. The channel design and surface properties enable automatic liquid transport from reservoirs through the emulsion formation zone, making the system self-sufficient and eliminating the need for complex pump connections

Inventive Principle:

Principle #25Self-service

2Speed

If negative pressure is applied to drive liquids in conventional microfluidic devices, then liquid movement can be achieved, but additional pressure control equipment and connections are required

Engineering Contradiction:

Improveliquid flow rateVSAvoidoperation simplicity

Core Design Contradiction:

SpeedVSEase of operation

Solution Approach 1:

The patent replaces the mechanical pressure control system (syringe pumps applying negative pressure) with a passive capillary action system. The mechanical pumping action is substituted by surface tension-driven capillary forces inherent to the microchannel structure, eliminating the need for pressure control equipment and simplifying operation while maintaining liquid flow

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If multiple narrow tubes are used to connect syringe pumps to microfluidic channels, then liquid delivery is achieved, but the assembly becomes complicated and less portable

Engineering Contradiction:

Improveliquid delivery capabilityVSAvoidassembly simplicity

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent merges the liquid delivery function directly into the microfluidic channel structure itself, eliminating the need for separate narrow connecting tubes. The channels are integrated into the substrate with reservoirs positioned directly at channel entrances, combining what were previously separate components (tubes, pumps, channels) into a unified, portable device that maintains liquid delivery capability

Inventive Principle:

Principle #5Merging (Combining)

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

Enables the generation of monodisperse emulsions using negative pressure without the need for syringe pumps, simplifying the assembly and operation of the device while ensuring consistent droplet formation in the emulsion forming zone.

Implementation Method 1

the first liquid is drawn into the first sub-channel through the first capillary inlet by virtue of capillary action of the first liquid

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

The suction member is configured to provide a predetermined suction force such that the second liquid in the second sub-channel is permitted to penetrate into the first liquid in the main channel so as to break up into droplets

Methodology Applied

Scientific EffectSuction force (negative pressure): Pressure Gradient

Implementation Method 3

The suction member is made from a shape memory polymer, and is disposed downstream of the outlet

Methodology Applied

Scientific EffectShape memory polymer transformation: Shape Memory Polymer

Data Source

PatentUS10189022B2Microfluidic device

Publication Date: 2019.01.29 NATIONAL TSING HUA UNIVERSITY

AI summary

A microfluidic device includes a substrate, first and second capillary inlets, a microfluidic channel unit, an outlet disposed downstream of the microfluidic channel unit, and a suction member disposed downstream of the outlet. A first liquid is drawn into a first sub-channel and a main channel of the microfluidic channel unit through the first capillary inlet. A second liquid is drawn into a second sub-channel of the microfluidic channel unit through the second capillary inlet. The suction member provides a predetermined suction force to permit the second liquid to penetrate into the first liquid and to break up into droplets in the first liquid, thereby generating monodisperse emulsions.