EWOD Droplet Interface Bilayers for In-Device Concentration Control

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Solution Overview

Problem

Existing EWOD devices face challenges in efficiently concentrating or diluting fluid droplets within the device due to their enclosed nature, making it difficult to alter droplet sizes or concentrations, and extracting specific components from reaction droplets for further reactions or analysis.

Innovation Solution

A method involving the formation of a droplet interface bilayer (DIB) between two droplets with different osmotic pressures, allowing solvent or solute transfer through the bilayer by electro-wetting, enabling concentration or dilution of droplets and extraction of desired components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If droplets are manipulated in an enclosed EWOD device, then device integration is improved, but ability to alter droplet concentrations and sizes is worsened

Engineering Contradiction:
Improvedevice integrationVSAvoiddroplet concentration and size adjustment
Core Design Contradiction:
Extent of automationVSAdaptability or versatility

Solution Approach 1:

A droplet interface bilayer (DIB) is introduced as an intermediary structure between two droplets. The DIB acts as a semi-permeable membrane that allows controlled transfer of solvents and solutes between droplets, enabling concentration and dilution operations within the enclosed device without requiring external access.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the physical and chemical parameters of the droplet interface by forming a bilayer structure with specific permeability properties. This allows control over the transfer of substances between droplets, enabling alteration of droplet concentrations and sizes while maintaining enclosure.

Inventive Principle:
Principle #35Parameter changes

2Extent of automation

If droplets are manipulated in an enclosed EWOD device, then device integration is improved, but ability to extract specific components is worsened

Engineering Contradiction:
Improvedevice integrationVSAvoidcomponent extraction
Core Design Contradiction:
Extent of automationVSEase of operation

Solution Approach 1:

The droplet interface bilayer serves as a selective intermediary that facilitates the extraction of specific components. By controlling the permeability of the bilayer, specific solutes can be transferred from one droplet to another, enabling targeted extraction and replenishment operations within the enclosed device.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If droplet interface bilayer is formed between two droplets, then solvent or solute transfer is enabled, but device complexity is increased

Engineering Contradiction:
Improvedroplet concentration and size alterationVSAvoiddroplet manipulation process
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The formation of a droplet interface bilayer merges two droplets into a single functional unit where controlled物质 transfer can occur. This combining approach enables concentration and dilution operations without requiring separate manipulation systems, thereby reducing overall device complexity while maintaining productivity.

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

Facilitates efficient alteration of droplet concentrations and sizes within EWOD devices, allowing for targeted extraction or replenishment of solutes, and separation of droplets for further reactions or analysis.

Implementation Method 1

allow a solvent species to pass from the first droplet to the second droplet via the droplet interface bilayer

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 2

selectively actuating the electro-wetting electrodes to: cause first and second droplets in a fluid medium in the fluid chamber of the EWOD device to contact each other

Methodology Applied
Scientific EffectElectro-wetting: Electrowetting

Data Source

PatentEP3756762B1Method of manipulating droplets in a microfluidic device
Publication Date: 2025.08.06 SHARP LIFE SCI EU LTD
  • EP3756762B1 patent drawingFigure 1
  • EP3756762B1 patent drawingFigure 2
  • EP3756762B1 patent drawingFigure 3

AI summary

The disclosure provides a method of manipulating droplets in an electro-wetting on dielectric (EWOD) device. Electro-wetting electrodes of the EWOD device are selectively actuated to: cause first and second droplets in a fluid medium in the fluid chamber of the EWOD device to contact each other to form a droplet interface bilayer, the first droplet containing fluid of a first composition including a first solute species and the second droplet containing fluid of a second composition different to the first composition, maintain the first and second droplets contacting each other to maintain the droplet interface bilayer and thereby allow the first solute species to pass from the first droplet to the second droplet via the DIB; and cause the first droplet to separate from the second droplet. This method aspect results in transfer of solute from the first droplet to the second droplet. This provides a convenient way of altering the concentration of a particular component or components in a fluid droplet within an EWOD device. This allows, for example, an undesired solute species to be extracted from a reaction droplet or the undesired solute species to be diluted in the reaction droplet before the droplet undergoes further reaction steps.