Milli-system Fluid Fractionation via Recirculation Zone
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Solution Overview
Problem
Current microfluidic systems are limited in their ability to fractionate large volumes of fluid containing particles, particularly in biological samples, as existing passive and active fractionation techniques are unsuitable for rare analytes and require laboratory settings, leading to inefficiencies and constraints such as sample degradation and equipment limitations.
Innovation Solution
A milli-system device with a cylindrical reservoir and a splitter body that creates a recirculation zone through a sudden section reduction, allowing for the separation of fluid into enriched and depleted phases using a partition and extraction means, enabling the extraction of a volume of interest without the need for external laboratory fractionation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If passive or active fractionation techniques are used in microfluidic systems, then fractionation efficiency is improved, but the processability of large volumes of fluid containing particles deteriorates
Solution Approach 1:
The device divides the fluid stream into multiple discrete droplets using a T-junction geometry. Each droplet acts as an independent reaction chamber, allowing parallel processing of multiple samples simultaneously. This segmentation enables the system to handle large total volumes while maintaining precise fractionation control in each individual droplet.
Solution Approach 2:
The invention transitions from planar 2D microfluidic channels to a 3D droplet-based system. By moving the fractionation process into the temporal dimension through sequential droplet generation and manipulation, the system achieves both high fractionation efficiency and large volume processing capability that cannot be obtained in traditional 2D microfluidic devices.
2Manufacturing precision
If fractionation is performed in laboratory settings with centrifugation or filtration, then separation quality is improved, but processing time and operational complexity increase
Solution Approach 1:
The invention replaces complex mechanical laboratory equipment (centrifuges, filtration systems) with a simplified droplet-based fractionation mechanism. The T-junction geometry and controlled fluid flow replace mechanical separation forces, achieving comparable separation quality without the need for heavy equipment and reducing processing time significantly.
Solution Approach 2:
The system changes the physical parameters of the fluid system by creating discrete droplets with controlled sizes and spacing. This parameter change enables fractionation to occur through simple fluid dynamics rather than requiring complex mechanical separation processes, thereby reducing both time and operational complexity while maintaining separation quality.
3Measurement precision
If fractionation is performed in laboratory settings, then separation accuracy is improved, but sample degradation risk and operational constraints increase
Solution Approach 1:
The device performs fractionation immediately upon sample introduction, before the sample has time to degrade. The rapid droplet generation and inline fractionation eliminate the waiting time inherent in laboratory workflows, preserving sample integrity while maintaining high separation accuracy through precise droplet manipulation.
Solution Approach 2:
The droplet acts as an intermediary carrier that protects the sample during fractionation. By encapsulating the fluid sample in discrete droplets, the system minimizes exposure to degrading environmental factors while enabling accurate fractionation through controlled droplet manipulation and merging operations.
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 efficient separation of fluid into enriched and depleted phases within the device, facilitating the analysis of large volumes of biological samples without the need for external laboratory processing, thereby overcoming previous limitations and improving sample handling and analysis efficiency.
Implementation Method 1
a section of the fractionating body abruptly reducing to a height less than one-tenth of its height at the level of its downstream end to form a flat base; the fractionation body defining, together with the reservoir, a first channel forming a zone restricting the flow of the fluid and opening at said flat base onto a zone of geometric singularity, that is to say, a sudden widening of the section in which the fluid can pass downstream of the flat base, said zone of geometric singularity forming a fluid recirculation zone
Implementation Method 2
extraction means, located downstream of the fractionating body, intended to separate and extract the depleted volume and the enriched volume
Data Source
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AI summary
A device for fractionation of a fluid containing particles and extraction of a particle-lean volume and a particle-rich volume, including: a cylindrical reservoir including an inlet orifice to supply the reservoir with fluid in a pumping direction from first to second ends of the reservoir; a fractionation body extending along a central axis of the reservoir, an upstream end positioned in vertical alignment above the inlet orifice, a cross section of the fractionation body reducing sharply at its downstream end; the fractionation body defining, with the reservoir, a first passage opening at the downstream end onto a recirculation zone with a geometric singularity; and an extraction mechanism downstream of the fractionation body to separate and extract the lean and rich volumes, including a partition delimiting an extraction volume configured, as fluid circulates in the pumping direction, to receive the particle-lean phase formed in the recirculation zone.