Microfluidic Droplet Inflation via Interface Disruption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current microfluidic systems are limited in their ability to significantly increase the volume of droplets beyond twice their initial size, which restricts the applicability and performance of droplet-based microfluidics for processes like enzymatic assays and dilution of substances.

Innovation Solution

A microfluidic device with a system comprising a microfluidic channel, fluid reservoirs, inflators, and inflator nozzles, featuring a region of expansion at the inflator nozzle/microfluidic channel interface to accommodate inflated droplets, allowing controlled inflation of droplets by disrupting the interface between the droplet and inflation fluid using mechanisms like electrodes or passive methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If picoinjection is used to increase droplet volume, then synchronization problem is solved, but droplet volume can only be increased to more than twice its initial volume

Engineering Contradiction:
Improvedroplet volumeVSAvoidvolume increase capability
Core Design Contradiction:
Volume of moving objectVSProductivity

Solution Approach 1:

The system segments the droplet volume increase process into multiple stages using a series of inflators arranged along the microfluidic channel. Each inflator adds a controlled amount of inflation fluid to the droplet, allowing cumulative volume increase beyond what a single injection point can achieve. This segmentation enables progressive droplet inflation while maintaining control over the final volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary action by pre-positioning multiple inflators along the microfluidic channel before droplets enter the inflation zone. Each inflator is pre-configured with inflation fluid reservoirs and nozzles, ready to deliver controlled volumes of fluid at specific locations. This preliminary arrangement enables systematic volume increase without requiring complex real-time synchronization.

Inventive Principle:
Principle #10Preliminary action

2Volume of moving object

If droplet merger is used to increase droplet size, then larger droplets can be formed, but synchronization of droplet formation with injection is technically challenging

Engineering Contradiction:
Improvedroplet sizeVSAvoidsynchronization complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The system employs self-service mechanisms where passive structures within the microfluidic channel automatically facilitate droplet inflation without requiring complex active control. The channel geometry, including expansion regions and positioning features, is designed to naturally guide droplets to inflation zones and maintain proper alignment with inflator nozzles. This passive self-alignment eliminates the need for complex synchronization mechanisms while achieving consistent droplet volume increase.

Inventive Principle:
Principle #25Self-service

3Volume of moving object

If standard microfluidic channel is used, then device structure is simple, but inflated droplets cannot be accommodated due to channel dimensions

Engineering Contradiction:
Improvedroplet volumeVSAvoidchannel geometry compatibility
Core Design Contradiction:
Volume of moving objectVSShape

Solution Approach 1:

The microfluidic channel incorporates dynamic geometry changes through expansion regions that adapt to the growing droplet volume. The channel cross-sectional area increases in controlled zones along the flow path, allowing droplets to expand without encountering geometric constraints. This dynamic channel design maintains structural simplicity while accommodating significant droplet volume increases through strategically placed expansion sections.

Inventive Principle:
Principle #15Dynamics

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 increase of droplet volume by multiple times its initial volume, enhancing the performance and applicability of droplet-based microfluidics by allowing substantial dilution and partitioning of substances within droplets.

Implementation Method 1

a mechanism for disrupting an interface between a droplet and a fluid wherein the at least one microfluidic channel comprises one or more droplets flowing therein

Methodology Applied
Scientific EffectInterface disruption:

Data Source

PatentEP2948703B1System and method for performing droplet inflation
Publication Date: 2019.03.13 BIO RAD LABORATORIES INC
  • EP2948703B1 patent drawingFigure 1A~1B
  • EP2948703B1 patent drawingFigure 2
  • EP2948703B1 patent drawingFigure 3A~3D

AI summary

The present invention generally pertains to a system for performing droplet inflation, and methods and kits comprising the same. The system comprises at least one microfluidic channel comprising one or more droplets flowing therein, one or more fluid reservoirs, one or more inflators, one or more inflator nozzles, and at least one mechanism for disrupting an interface between a droplet and a fluid. The present invention provides for the inflation of a relatively controlled volume of fluid into a droplet resulting in an increase in the volume of the droplet relative to its volume prior to inflation and, accordingly, dilution of the concentration of species, if any, previously present and emulsified in the droplet.