Elastic Membrane Recirculation for Microfluidic Disc Sample Mixing
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Solution Overview
Problem
Current centrifugal disc platforms inefficiently utilize and mix liquid samples, limiting detection capabilities due to low Reynolds number and partial exposure of samples, especially in point-of-care scenarios.
Innovation Solution
A recirculation mechanism using an elastic membrane in a centrifugal disc platform that stores pneumatic energy to facilitate circular movement and mixing of the entire liquid sample, enabling efficient reuse and detection methods like flow injection analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reciprocation system is used to enhance detection sensitivity, then the limit of detection is improved, but the sample utilization is insufficient because only the middle part of the sample is exposed to the detection array
Solution Approach 1:
The patent inverts the traditional reciprocation motion by implementing continuous circular rotation of the centrifugal disc. Instead of back-and-forth linear motion that only exposes the middle sample portion, the circular rotation ensures the entire liquid sample continuously passes over the detection array, maximizing sample utilization while maintaining detection sensitivity.
Solution Approach 2:
The patent implements continuous recirculation of the liquid sample through the detection array via circular rotation, eliminating the intermittent exposure of reciprocation systems. The sample continuously flows over the detection array multiple times, ensuring complete sample utilization and sustained detection capability throughout the assay process.
2Speed
If reciprocation motion is used to move the sample, then the sample is transported to the detection array, but the sample is not adequately mixed due to low Reynolds number
Solution Approach 1:
The patent transitions from static or reciprocating motion to dynamic continuous rotation. The centrifugal disc rotates at controlled speeds, creating dynamic flow conditions that enhance mixing through centrifugal forces while maintaining adequate sample transport to the detection array. The rotational speed can be adjusted to optimize both transport and mixing effects.
3Measurement precision
If the entire liquid sample is to be recirculated and mixed, then detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent employs passive recirculation utilizing centrifugal forces generated by the rotating disc itself, rather than requiring external pumps or complex active control systems. The centrifugal force naturally drives the liquid sample in circular motion, enabling self-powered recirculation that enhances detection accuracy while minimizing additional device complexity.
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 mechanism maximizes sample utilization and mixing efficiency, allowing for repeated exposure of the entire sample to detection arrays and supporting various detection methods.
Implementation Method 1
The liquid directed into the pressure chamber may inflate the elastic membrane to store pneumatic energy
Implementation Method 2
When the CD platform spins at a high RPM, the liquid may be directed from the reservoir downstream through the input channel, over the detection array, and into the pressure chamber
Data Source
AI summary
The present invention is directed to a recirculation system for use in microfluidic centrifugal disc platforms for reusing and mixing an entire sample. The present invention features a system comprising a reservoir, an input channel, a detection array, a pressure chamber, and a recirculation channel connecting the pressure chamber to the reservoir. The recirculation channel may have a resistance lower than the channel upstream resistance. When the CD platform spins at a high RPM, the liquid may be directed from the reservoir into the pressure chamber. When the RPM of the CD platform decreases rapidly, the liquid may be directed from the pressure chamber through the channel and through the recirculation channel to the reservoir, such that the liquid travels through the recirculation channel faster than the liquid travels through the channel.