Microfluidic Capillary Valve Droplet Isolation

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Solution Overview

Problem

Existing methods for determining optimal protein crystallization concentrations are cost-prohibitive due to the macro-sized volume requirements of traditional crystallization trays, making it expensive to test multiple solution concentrations, especially for expensive proteins.

Innovation Solution

A microfluidic device with capillary valves and chambers that allow for the selective introduction of different aqueous solutions based on pressure levels, preventing mixing and enabling precise control over the volume of each solution, thereby allowing for the simultaneous generation and storage of isolated droplets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional crystallization trays with macro-sized volumes are used, then protein crystallization testing can be performed, but the cost becomes prohibitive due to the large volume of expensive protein solutions required

Engineering Contradiction:

Improvevolume of protein solutionVSAvoidwaste of expensive protein

Core Design Contradiction:

Quantity of substanceVSLoss of substance

Solution Approach 1:

The device segments the macro-scale crystallization tray into multiple micro-scale chambers, each capable of holding isolated droplets. This segmentation allows testing of multiple concentrations using minimal total volume, directly resolving the contradiction between sufficient testing volume and waste reduction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an aqueous solution as an intermediary fluid that fills chambers and isolates droplets. This intermediary enables precise control over droplet formation and prevents mixing, allowing cost-effective testing while maintaining the ability to perform multiple crystallization experiments simultaneously.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If multiple aqueous solutions are mixed in traditional trays, then concentration variations can be achieved, but the solutions mix before reaching the testing area, reducing precision

Engineering Contradiction:

Improveconcentration control precisionVSAvoidsolution composition integrity

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent extracts the mixing function from the traditional tray system and replaces it with capillary valve-controlled sequential filling. This extraction prevents unwanted mixing while maintaining the ability to create precise concentration gradients, resolving the contradiction between concentration control and composition stability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical mixing process with a pressure-controlled valve system. By using capillary valves responsive to pressure changes, the system achieves precise concentration control without mechanical mixing, thereby maintaining solution composition integrity while enabling concentration variations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Area of stationary object

If macro-sized testing trays are used, then sufficient space for crystallization is provided, but the device complexity and cost increase

Engineering Contradiction:

Improvetesting areaVSAvoiddevice structure

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent transitions from a two-dimensional tray surface to a three-dimensional micro-chamber structure with vertical stacking of chambers. This dimensional change provides sufficient testing area and volume while compacting the device footprint, resolving the contradiction between testing space and device complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements nested chambers within a compact device structure, where multiple chambers are arranged in a space-efficient configuration. This nesting approach provides adequate testing area for crystallization while minimizing overall device complexity and size.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 efficient testing of multiple protein crystallization concentrations on a micro-scale, minimizing waste and reducing costs by allowing precise control over the introduction and separation of aqueous solutions within the device.

Implementation Method 1

The at least one capillary valve is configured to allow for the at least two different aqueous solutions to be introduced into the at least one chamber without mixing prior to entering the at least one chamber based at least in part on pressure levels of the at least two different aqueous solutions

Methodology Applied

Scientific EffectCapillary pressure: Capillary Pressure

Data Source

PatentUS11148140B2Devices for simultaneous generation and storage of isolated droplets, and methods of making and using the same

Publication Date: 2021.10.19 BRANDEIS UNIV

AI summary

A microfluidic device comprising at least one isolation unit and at least one capillary valve. The at least one isolation unit has at least one chamber. The at least one chamber configured to receive at least two different aqueous solutions. The at least one capillary valve is configured to allow for the at least two different aqueous solutions to be introduced into the at least one chamber without mixing prior to entering the at least one chamber based at least in part on pressure levels of the at least two different aqueous solutions.