Microfluidic Plasma Separation via Vertical Up-Flow Sedimentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional methods for blood plasma separation, such as centrifugation, are time-consuming, labor-intensive, and can lead to hemolysis of red blood cells, contaminating plasma and hindering accurate diagnostic analyses, while existing microfluidic techniques face challenges like complex fabrication and RBC leakage due to clogging at membrane filters.

Innovation Solution

A microfluidic device with a filter-in-top configuration using a vertical up-flow channel minimizes hemolysis by gravity-assisted cellular sedimentation, preventing RBCs from clogging the filter and allowing for efficient separation of plasma without hemolysis, suitable for point-of-care diagnostics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If centrifugation is used for blood plasma separation, then separation effectiveness is improved, but time consumption and labor intensity increase

Engineering Contradiction:

Improveseparation effectivenessVSAvoidtime consumption

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical centrifugation system with a microfluidic passive separation system that uses integrated microchannels and filtration structures. The microfluidic device achieves plasma separation through passive flow mechanisms and filtration rather than external mechanical centrifugal force, eliminating the need for centrifuges and reducing time consumption while maintaining separation effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the separation mechanism from centrifugal force-based to filtration-based microfluidic flow. By altering the physical parameters of the separation process (from high-speed rotation to controlled microfluidic flow through filters), the system achieves rapid plasma separation without the time-consuming centrifugation step.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If centrifugation is used for blood plasma separation, then separation effectiveness is improved, but hemolysis of red blood cells occurs

Engineering Contradiction:

Improveseparation effectivenessVSAvoidhemolysis

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the high-force mechanical centrifugation system with a gentle microfluidic filtration system. The microfluidic device uses passive flow through filtration structures rather than high-speed rotation, significantly reducing mechanical stress on red blood cells and preventing hemolysis while still achieving effective plasma separation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a membrane filter as an intermediary component between the blood sample and the separation process. The filter selectively allows plasma to pass through while retaining red blood cells, providing a gentle separation mechanism that avoids the direct high-force mechanical action of centrifugation that causes hemolysis.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If membrane filter-based separation is used, then simplicity and low fabrication cost are improved, but RBC clogging and hemolysis occur

Engineering Contradiction:

Improvefabrication simplicityVSAvoidRBC leakage and hemolysis

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the microfluidic device into multiple functional regions including pre-filtration channels, main filtration areas with membrane filters, and post-filtration collection channels. This segmentation allows different parts of the system to handle specific tasks, distributing the filtration load and preventing clogging at any single filter location while maintaining manufacturing simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent incorporates dynamic flow control features in the microfluidic channels, including varying channel widths and flow distribution structures that adaptively guide blood flow. This dynamic design prevents RBC accumulation and clogging by maintaining optimal flow velocity distribution across the filtration membrane, reducing hemolysis while keeping the device simple to manufacture.

Inventive Principle:

Principle #15Dynamics

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 device achieves high recovery of proteins and nucleic acids, comparable to conventional centrifugation methods, with minimal hemolysis and increased plasma volume, making it suitable for integration with downstream detection modules and use in resource-limited settings.

Implementation Method 1

gravity-assisted cellular sedimentation

Methodology Applied

Scientific EffectGravity: Gravitation

Implementation Method 2

gravity-assisted cellular sedimentation

Methodology Applied

Scientific EffectSedimentation: Sedimentation

Implementation Method 3

membrane filter-based blood plasma separation

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Data Source

PatentUS10596522B2Hemolysis-free blood plasma separation

Publication Date: 2020.03.24 RGT UNIV OF CALIFORNIA

AI summary

A simple and robust on-chip blood plasma separation device is provided. The device is configured to integrate with downstream detection modules and provides sample-to-answer microfluidic POC diagnostics devices.