Drop Separation via Osmotic Density Variation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for separating drops in large libraries of molecules or biological reactions are complex, expensive, and inefficient, particularly when dealing with large sample sizes or high-throughput screening, as they can only process up to 1000 to 10,000 drops per second, making them inadequate for rapid and simple implementation.

Innovation Solution

A method involving osmotic flow to vary the volume of drops, causing significant density changes in drops with reaction products, allowing for separation based on density variations, which enables quick and efficient isolation of active microreactors or products, even in high-throughput applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual or automatic sorting machines are used to separate drops, then separation can be achieved, but the process is complex and expensive with limited throughput of 1000 to 10000 drops per second

Engineering Contradiction:
ImprovethroughputVSAvoidseparation process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention changes the density parameter of drops by controlling osmotic flow through semi-permeable membranes. Drops containing reaction products undergo greater density changes than those without, enabling separation based on density variations. This approach replaces complex sorting machines with a simpler osmotic separation process that can handle much larger throughput.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces a semi-permeable membrane as an intermediary between drops and the surrounding medium. This membrane allows selective osmotic flow that mediates the density change process, enabling automatic separation without direct mechanical intervention. The membrane acts as a mediator that translates chemical reaction presence into physical density differences.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If osmotic flow is used to vary droplet volume as described in Lab on a Chip, then separation can be achieved, but the variation in droplet volume is small and the process is tedious and not very efficient

Engineering Contradiction:
Improveseparation efficiencyVSAvoidseparation time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The invention applies local quality by placing different semi-permeable membranes on different drops based on their contents. Drops containing reaction products receive membranes with different permeability characteristics than drops without products, creating localized quality differences that amplify osmotic flow effects and enable faster, more efficient separation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention introduces asymmetry by using drops of initially different volumes or applying membranes with different properties to different drops. This asymmetric treatment creates differential osmotic responses that amplify volume and density changes, making separation more efficient and reducing the time required compared to symmetric treatment of all drops.

Inventive Principle:
Principle #4Asymmetry

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

This method allows for rapid and simple separation of drops with significant reaction products from a large number, enabling high-throughput screening and efficient recovery of active microreactors or products, overcoming the limitations of existing techniques by achieving significant density variations and spontaneous separation.

Implementation Method 1

a) varying the volume of at least a first group of drops to be separated from among the drops to be separated by placing the drops in contact with a semi-permeable membrane in order to carry out an osmotic flow

Methodology Applied
Scientific EffectOsmotic flow: Osmosis

Implementation Method 2

The variation in density of the drops of the first group of drops after the osmotic flow step is greater than the initial polydispersity of the densities of the drops to be separated

Methodology Applied
Scientific EffectDensity variation: Density Gradient

Data Source

PatentEP2689012B1Method for high-throughput screening of drops by osmotic exchange and density variation
Publication Date: 2019.07.03 CENT NAT DE LA RECH SCI (C N R S)
  • EP2689012B1 patent drawingFigure 1
  • EP2689012B1 patent drawingFigure 2~3
  • EP2689012B1 patent drawingFigure 4

AI summary

This method comprises bringing drops to be separated into contact with an interface (40) suitable for allowing an osmotic equilibrium between the content of each drop to be separated. The method comprises an osmotic flow between the drops (20A) of the first group of drops through the interface (40) in order to modify the density of each drop (20A) of the first group of drops and the separation of the drops (20A, 20B) according to the density thereof or a combination of the density and the volume in order to isolate the drops (20A) of the first group of drops from the drops (20B) of a second group of drops.