Microfluidic Device Sizing for Neuron Confinement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for positioning and culturing neurons in microfluidic devices face challenges such as limited density, uncontrolled network architecture, and difficulty in separating cell bodies from axons, which restricts the study of neural networks and structure/function relationships.

Innovation Solution

A method for sizing a microfluidic device with a confinement zone and channels to optimize cell flow, allowing controlled positioning of neurons at desired densities by calculating sedimentation velocity, flow velocity, and pressure drops, ensuring adequate flow and minimizing cell loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional techniques are used for positioning neurons, then cell culture can be maintained, but the density and uniformity of cell positioning is limited

Engineering Contradiction:
Improveneuron densityVSAvoidpositioning uniformity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent employs microfluidic channels with controlled laminar flow to transport and position neuron suspensions. By regulating fluid flow rates and pressure gradients, the system achieves precise control over neuron distribution, enabling high density (n>100 cells/ml) while maintaining uniform spatial positioning through hydrodynamic forces rather than mechanical manipulation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The invention optimizes multiple parameters including flow velocity, channel geometry, and suspension concentration to control neuron positioning. By adjusting these parameters, the system transitions from random distribution to controlled uniform positioning, simultaneously increasing neuron density and positioning precision within the microfluidic confinement zone.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If microfluidic chips with micro-pillars are used to isolate neurons, then spatial positioning is improved, but the complexity of the device increases

Engineering Contradiction:
Improvespatial positioningVSAvoiddevice structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent removes complex structural elements like micro-pillars and replaces them with simplified microfluidic channel geometries. The confinement zone uses straightforward channel walls and boundaries to achieve spatial positioning, eliminating the need for intricate three-dimensional structures while maintaining positioning precision through controlled fluid flow and channel design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using physical micro-pillar structures for isolation, the invention employs laminar fluid flow and hydrodynamic confinement to achieve neuron positioning. This hydraulic approach replaces complex mechanical structures with simpler fluid-based control, reducing device complexity while maintaining spatial positioning capabilities.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Shape

If silicone beads are used for neuron deposition, then network architecture can be built, but the density and control of neuron positioning is limited

Engineering Contradiction:
Improvenetwork architectureVSAvoidneuron density
Core Design Contradiction:
ShapeVSQuantity of substance

Solution Approach 1:

The patent uses microfluidic channels to transport neuron suspensions and control their deposition patterns. By regulating flow rates and channel geometry, the system achieves high neuron density while maintaining controlled network architecture formation, overcoming the density limitations of silicone bead methods through precise hydrodynamic control.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The invention optimizes suspension concentration, flow velocity, and channel dimensions to simultaneously achieve high neuron density and controlled network architecture. By adjusting these parameters, the system forms organized neural networks with precise spatial arrangement and high cell density, unlike the uncontrolled deposition with silicone beads.

Inventive Principle:
Principle #35Parameter changes

4Shape

If multiple culture levels are used to assemble neurospheroids, then tissue blocks can be formed, but the process time increases and density control is lost

Engineering Contradiction:
Improvetissue block formationVSAvoidculture process time
Core Design Contradiction:
ShapeVSLoss of time

Solution Approach 1:

The patent divides the microfluidic device into specialized zones (inlet, confinement, outlet) that work together in a single integrated flow path. This segmentation allows neurons to be transported, confined, and organized into tissue-like structures in one continuous process, eliminating the need for multiple separate culture steps and significantly reducing processing time while maintaining density control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses continuous laminar flow to transport and organize neurons into confined zones where they form tissue-like structures. This hydraulic approach enables single-step formation of organized neural tissues, replacing the multi-level assembly process of neurospheroids and reducing culture time while maintaining control over cell density and spatial organization.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 uniform and controlled confinement of neurons in microfluidic chambers, facilitating the study of neural networks by maintaining cell distribution and optimizing fluid flow, thereby overcoming previous limitations in density and separation.

Implementation Method 1

calculation of the sedimentation velocity v sedi of a particle or cell

Methodology Applied
Scientific EffectSedimentation: Sedimentation

Implementation Method 2

determination of the velocity v ch of the carrier fluid medium in said confinement zone

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Implementation Method 3

a confinement zone (or deposition chamber) in which at least one part of the sample is confined

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP3365426B1Sizing of a microfluidic device for confining a sample
Publication Date: 2022.03.30 CENT NAT DE LA RECH SCI (C N R S)
  • EP3365426B1 patent drawingFigure 1~2
  • EP3365426B1 patent drawingFigure 3
  • EP3365426B1 patent drawingFigure 4~5

AI summary

The present invention relates to a method for sizing a microfluidic device for confining a sample. The sample to be confined can include cells (biological sample) or microparticles suspended in a carrier fluid medium. The present invention also relates to a method for sizing a microfluidic device for confining an explant contained in a cell culture fluid medium.