Microfluidic Manifold Side Channels 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 obstructions, utilizes laminar flow and capillary action to separate plasma from cellular components, followed by dilution to achieve high separation efficiency and appropriate concentration for diagnostic testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional microfluidic devices are used for plasma extraction, then plasma separation is achieved, but separation efficiency is low and plasma yield is low
Solution Approach 1:
The device segments the flow path into a main channel for cellular components and multiple plasma channels for plasma collection. The side channels are strategically positioned and sized to selectively extract plasma while retaining cells in the main channel, achieving both high separation efficiency and plasma yield simultaneously
Solution Approach 2:
The side channels have specific diameter constraints (at most 200 μm at narrowest cross-section) to create local quality differences in the flow path. This localized geometric control enables selective plasma extraction at specific locations while maintaining overall flow dynamics for high yield
2Productivity
If conventional microfluidic devices extract plasma from undiluted whole blood, then plasma is obtained, but samples are impure and require further processing
Solution Approach 1:
The device extracts only the plasma portion from whole blood through the side channels, leaving cellular components in the main channel. This selective extraction achieves high sample purity (separation efficiency ≥95%) while maintaining fast extraction speed from undiluted whole blood
Solution Approach 2:
The side channels function as porous-like structures with specific diameter constraints that allow plasma to pass through while blocking cellular components. This passive filtration mechanism achieves purification without requiring additional processing steps
3Speed
If plasma is extracted without dilution, then extraction speed is maintained, but concentration is inappropriate for diagnostic testing
Solution Approach 1:
The device performs dilution as a preliminary action immediately after plasma extraction within the same microfluidic system. Dilution channels are integrated to mix extracted plasma with dilution buffer, achieving appropriate concentration for diagnostic testing while maintaining fast overall processing speed
Solution Approach 2:
The device merges multiple functions (extraction, separation, and dilution) into a single integrated microfluidic system. This combination eliminates the need for separate processing steps, maintaining fast extraction speed while ensuring appropriate plasma concentration for diagnostic applications
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 microfluidic manifold achieves a separation efficiency of at least 95% and provides a cost-effective, fast method for preparing plasma samples, suitable for use in low-resource settings, with minimal cellular components and appropriate concentration for diagnostic testing.
Implementation Method 1
Each of the plurality of side channels has an average diameter of at most 200 μm at a narrowest cross section
Implementation Method 2
The isolation of blood plasma, essentially the extracellular matrix of the larger blood cells, from whole blood
Implementation Method 3
utilizes laminar flow and capillary action 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%.