Microfluidic Manifold Layout for High-Purity Plasma Extraction
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Solution Overview
Problem
Existing microfluidic devices for isolating blood plasma from whole blood suffer from low plasma yield and separation efficiency, resulting in impure samples that require further processing, and do not effectively handle undiluted whole blood.
Innovation Solution
A microfluidic manifold with a plasma extraction chamber and dilution chamber, featuring specific channel diameters and geometries, uses laminar flow and momentum to separate plasma from cellular components, and a dilution chamber for preparing samples at appropriate concentrations for testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional microfluidic devices are used for plasma extraction, then device simplicity is maintained, but separation efficiency is low and plasma yield is low
Solution Approach 1:
The device is segmented into multiple functional zones within the extraction chamber: a main channel for whole blood flow, multiple side channels for plasma extraction, and a collection channel. This segmentation allows different separation mechanisms to operate in different zones, achieving high separation efficiency through structured complexity rather than monolithic design
Solution Approach 2:
The invention transitions from two-dimensional planar channels to three-dimensional vertical stacking with the extraction chamber positioned above the collection channel. Plasma extracts through vertical side channels from the main channel into the collection channel below, utilizing the third dimension to achieve high separation efficiency while maintaining compact device footprint
2Productivity
If side channels with larger diameter are used, then plasma flow rate increases, but separation efficiency decreases
Solution Approach 1:
Different channel regions have different diameters optimized for their specific functions: side channels have smaller diameters (50-200 μm) at their narrowest sections to maintain separation efficiency and prevent cell passage, while the main channel and collection channel have larger diameters to accommodate high flow rates. This local optimization allows simultaneous achievement of high plasma yield and high separation efficiency
Solution Approach 2:
The side channel diameter varies along its length, being smaller at the extraction point to ensure separation efficiency and larger at the connection points to maintain flow rate. This parameter variation along the channel length resolves the contradiction between plasma yield and separation efficiency by adapting the diameter to local flow and separation requirements
3Quantity of substance
If undiluted whole blood is processed, then sample volume is maximized, but separation efficiency is low
Solution Approach 1:
The extraction chamber is designed with multiple side channels positioned at different locations along the main channel, allowing plasma to be extracted continuously as blood flows through. This preliminary extraction architecture processes undiluted whole blood effectively from the start, maximizing plasma volume without requiring pre-dilution, and achieves high separation efficiency through the structured multi-channel design
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
Achieves high separation efficiency (>95%) and effective plasma extraction and dilution directly from whole blood, producing pure plasma samples suitable for diagnostic analysis.
Implementation Method 1
uses laminar flow and momentum to separate plasma from cellular components
Implementation Method 2
uses laminar flow and momentum to separate plasma from cellular components
Data Source
AI summary
An extraction chamber includes a main channel, a plasma channel, and a plurality of side channels fluidly connecting the main channel to the plasma channel. Each of the plurality of side channels has an average diameter of at most 200 μm at a narrowest cross section, and the extraction chamber has a separation efficiency of at least 95%. A multilevel extraction chamber, includes a main channel, a secondary channel fluidly connected to the main channel, a plasma channel fluidly connected to the secondary channel, a first set of a plurality of side channels fluidly connecting the main channel to the secondary channel, and a second set of a plurality of side channels fluidly connecting the secondary channel to the plasma channel. Each of the first set of side channels has an average diameter that is greater than the average diameter of each of the second set of side channels, and the extraction chamber has a separation efficiency of at least 95%.