H-type Microfluidic Filter for Bubble-Free Biophysical Analysis
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Solution Overview
Problem
Microfluidic systems face challenges with air entrapment and bubble formation during priming, leading to inaccurate and imprecise measurements due to complex and costly optical systems required for simultaneous optical detection across multiple circuits, and issues with background signal interference affecting sample analysis.
Innovation Solution
A microfluidic apparatus with a distribution channel configured for lateral distribution of sample fluid into auxiliary fluid, featuring capillary channels and a switchable pressure source for controlled fluid flow, allowing for sequential or simultaneous measurement of biophysical properties while minimizing background signal interference and preventing bubble formation through capillary filling and expansion features at ports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple samples are run in parallel on separate microfluidic circuits to increase throughput, then productivity is improved, but device complexity increases due to the need for complex and costly optical systems to detect all circuits simultaneously or near simultaneously
Solution Approach 1:
The patent divides the detection process into sequential segments, where a single optical detector measures samples in one microfluidic circuit at a time, then moves to the next circuit. This segmentation allows multiple samples to be processed in parallel while using a single, simpler optical system rather than requiring complex simultaneous multi-circuit detection systems.
2Measurement precision
If detection regions are expanded to increase the volume of fluid available for optical detection, then measurement precision is improved, but background signal interference increases affecting sample analysis accuracy
Solution Approach 1:
The patent applies local quality by creating a localized detection region within the microfluidic circuit where the optical detector measures samples. The H-filter configuration concentrates the sample and auxiliary fluid flows into a specific lateral distribution zone, allowing the detector to focus on a small, well-defined area with minimal background signal from chip materials, while still achieving sufficient detection volume through the concentrated fluid flows.
3Device complexity
If auxiliary fluid flow reaches the junction before sample fluid flow during priming, then device complexity is reduced, but measurement precision deteriorates due to air trap formation rendering the microfluidic chip defective
Solution Approach 1:
The patent applies preliminary action by designing the system to first fill the entire microfluidic circuit with auxiliary fluid through capillary action before introducing the sample fluid. This preliminary filling of the distribution channel and capillary channels with auxiliary fluid ensures that when sample fluid is later introduced, it will not encounter air traps at the junction, preventing measurement defects while maintaining simple priming procedures.
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 solution enables cost-effective, accurate, and precise biophysical property measurements by reducing the complexity of optical systems, minimizing background signal interference, and ensuring bubble-free operation, thus improving the sensitivity and accuracy of sample analysis.
Implementation Method 1
the distribution channel is configured to enable a lateral distribution of the components from the sample fluid flow into the auxiliary fluid flow
Implementation Method 2
a method and apparatus for optimising capillary filling of a microfluidic circuit to improve the accuracy and/or precision of sample measurements
Data Source
AI summary
A flow apparatus for measuring at least one biophysical property of one or more components is provided. The apparatus comprises one or more microfluidic devices. Each microfluidic device comprises: a sample channel having a sample inlet port for introducing a sample fluid flow comprising one or more components at a first flow rate into an elongate distribution channel, an auxiliary channel having an auxiliary inlet port for introducing an auxiliary fluid flow at a second flow rate into the elongate distribution channel. The distribution channel is configured to enable a lateral distribution of the components from the sample fluid flow into the auxiliary fluid flow. Each microfluidic device further comprises two or more capillary channels provided downstream and in fluid communication with the distribution channel, at least one outlet port provided downstream of each of the capillary channels. The sample inlet port and/or the outlet port further comprises an expansion feature between the channel and the corresponding port, whereby the expansion feature comprises a tapered section adjacent to the channel and a curved section adjacent to the port. The apparatus further comprises a switchable pressure source configured to control the flow of the fluids through the channels; and a detector configured to detect and measure at least one biophysical property of the or each component sequentially or simultaneously in each of the capillary channels and/or outlet ports on the microfluidic device.