Microfluidic Droplet Formation via Segmented Conduits

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Solution Overview

Problem

Current methods for producing multiple emulsions lack consistency in droplet size and number, and control over nesting levels, making them less viable for commercial applications in industries like pharmaceuticals, cosmetics, and food.

Innovation Solution

A microfluidic system that forms multiple emulsions by flowing three or more fluids through conduits, allowing for precise control over droplet formation and nesting levels, with the ability to produce droplets of consistent size and number, and varying fluid viscosities to achieve desired emulsion structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If two-stage emulsification technique is used to produce multiple emulsions, then emulsion formation is achieved, but droplet size and number consistency is poor

Engineering Contradiction:
Improvedroplet size consistencyVSAvoiddroplet size and number consistency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The device segments the emulsification process into distinct spatial zones: an inner conduit for continuous phase flow and an outer conduit for dispersed phase flow. This segmentation allows independent control of each phase, enabling precise control over droplet formation parameters and consistent droplet size and number.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention replaces traditional mechanical mixing methods (shear forces through mixing) with a flow-based system where droplets form automatically due to fluid dynamics in the concentric conduit arrangement. This substitution eliminates the variability associated with mechanical mixing while maintaining reliable droplet formation.

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

2Adaptability or versatility

If traditional emulsification methods are used, then multiple emulsions are formed, but control over nesting levels is insufficient

Engineering Contradiction:
Improvecontrol over nesting levelsVSAvoidnesting level control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The device employs a nested conduit structure where an inner conduit is positioned within an outer conduit. This nested geometry enables the formation of multiple emulsion layers (e.g., water-in-oil-in-water) with precise control over nesting levels, as each conduit layer corresponds to a specific emulsion interface.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention applies different fluid phases and flow conditions to different spatial locations within the device. The inner conduit region and outer conduit region can have different fluid compositions, viscosities, and flow rates, allowing precise local control over emulsion formation and nesting structure.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If membrane emulsification technique is used, then water-in-oil-in-water emulsions are produced, but droplet size control and consistency are limited

Engineering Contradiction:
Improvedroplet size controlVSAvoiddroplet size control and consistency
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The device enables independent adjustment of multiple parameters including flow rates of inner and outer phases, conduit dimensions, and fluid viscosities. By changing these parameters, droplet size can be precisely controlled and reproduced, achieving both ease of manufacture and consistent droplet size without requiring complex membrane structures.

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

Enables the production of multiple emulsions with precise control over droplet size and number, and fluid viscosities, enhancing their applicability in industries by ensuring consistent and predictable delivery of encapsulated substances.

Implementation Method 1

An emulsion is a fluidic state which exists when a first fluid is dispersed in a second fluid that is typically immiscible or substantially immiscible with the first fluid

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP2136786B8Apparatus for forming droplets
Publication Date: 2012.11.14 PRESIDENT & FELLOWS OF HARVARD COLLEGE

AI summary

The present invention generally relates to emulsions such as multiple emulsions, and to methods and apparatuses for making emulsions, and techniques for using the same. A multiple emulsion generally describes larger droplets that contain one or more smaller droplets therein which, in some cases, can contain even smaller droplets therein, etc. Emulsions, including multiple emulsions can be formed in certain embodiments with generally precise repeatability, and can be tailored to include any number of inner droplets, in any desired nesting arrangement, within a single outer droplet. In addition, in some aspects of the invention, one or more droplets may be controllably released from a surrounding droplet.