Siloxane Block Copolymer Surfactant for Microfluidic Droplet Control

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Solution Overview

Problem

Microfluidic devices face challenges in achieving efficient droplet operations and maintaining surface tension within the desired range for biomedical applications, as conventional surfactants can inhibit chemical reactions and have compatibility issues with reagents.

Innovation Solution

The use of siloxane-based block co-polymer surfactants, such as CMS-222, which are soluble in PDMS filler fluids but not in aqueous buffers, to adjust the interfacial tension and maintain a surface tension of 6-12 dynes/cm, ensuring efficient droplet formation and movement without interfering with biological functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional surfactants are used to adjust surface tension, then droplet formation and movement are improved, but chemical reactions are inhibited and compatibility with reagents deteriorates

Engineering Contradiction:

Improvedroplet formation and movementVSAvoidinhibition of chemical reactions

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the surfactant by using siloxane-based block copolymers with specific molecular structures (containing hydrophilic and hydrophobic segments) instead of conventional surfactants. This parameter change allows the surfactant to achieve the desired surface tension adjustment while maintaining compatibility with biological reagents and not interfering with chemical reactions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material design by creating siloxane-based block copolymers that combine different functional segments (hydrophilic and hydrophobic) within a single molecular structure. This composite approach enables the surfactant to simultaneously interact with both aqueous phases and oil phases while being biocompatible, thus resolving the contradiction between surfactant effectiveness and chemical reaction compatibility.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If surfactants are added to maintain surface tension, then droplet operations are enhanced, but compatibility with biomedical reagents deteriorates

Engineering Contradiction:

Improvedroplet operationsVSAvoidcompatibility with reagents

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent modifies the chemical parameters of the surfactant by selecting siloxane-based block copolymers with specific molecular weights and hydrophilic-lipophilic balances. These parameter changes ensure that the surfactant maintains effective surface tension control for droplet operations while being chemically compatible with a wide range of biomedical reagents, thereby improving adaptability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs siloxane-based block copolymers that can be easily removed or degraded after serving their surfactant function. These surfactants are designed to be transient, allowing them to perform their droplet manipulation function and then be discarded or metabolized without leaving harmful residues, thus maintaining reagent compatibility throughout the experiment.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Stress or pressure

If conventional surfactants are used, then interfacial tension is adjusted, but adverse effects on biological functions occur

Engineering Contradiction:

Improveinterfacial tensionVSAvoidadverse effects on biological functions

Core Design Contradiction:

Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the molecular parameters of the surfactant by using siloxane-based block copolymers with specific structural features (siloxane backbone with hydrophilic side chains). These parameter changes result in a surfactant that effectively adjusts interfacial tension while being biologically inert, thus eliminating adverse effects on biological functions while maintaining the required tension control.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of conventional surfactants (biological interference) into a benefit by using siloxane-based block copolymers that are specifically designed to be biocompatible. The surfactant's ability to adjust interfacial tension is maintained, but the harmful biological effects are transformed into beneficial neutrality, allowing the surfactant to function without interfering with biological processes.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The siloxane-based block co-polymer surfactants enhance droplet operations by maintaining the target surface tension, improving droplet formation and movement within microfluidic devices, while being compatible with biomedical applications and avoiding adverse effects on chemical reactions.

Implementation Method 1

Methodology Applied

Scientific EffectSurfactant: Surfactant

Data Source

PatentEP3365108B1Filler fluid for fluidic devices

Publication Date: 2024.06.12 ILLUMINA CAMBRIDGE LTD

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AI summary

Disclosed herein are compositions and fluidic devices that include a filler fluid having a siloxane block co-polymer solubilized in the filler fluid. Also disclosed herein are related kits and methods for using the fluidic devices for various uses, such as the polymerase chain reaction or preparations for sequencing reactions.