Multiplexed Microfluidic Photometric Module for Bubble-Free Assays
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Solution Overview
Problem
Current microfluidic photometric systems face challenges in reducing the volume of liquid samples required for measurements, improving measurement accuracy and precision, and achieving low per-test costs while enabling multiplexing and integration with other analytical systems for comprehensive data acquisition from a single sample.
Innovation Solution
The development of a microfluidic device with a multiplicity of unidirectional-flux cuvettes that share a common fluidic outlet, designed to minimize air-bubble formation and facilitate complete sample removal and reuse, using fluidic valves to immobilize samples during measurements and maintain pressure to prevent displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple cuvettes are used for multiplexed photometric measurements, then the ability to perform multiple assays from a single sample is improved, but the volume of liquid sample required increases
Solution Approach 1:
Multiple cuvettes are merged into a single integrated microfluidic chip with shared fluidic pathways, allowing multiple assays to be performed simultaneously using a single small-volume sample input. The chip integrates multiple reaction chambers, fluidic channels, and outlets into one compact device.
Solution Approach 2:
The microfluidic chip employs a nested structure where multiple cuvettes are arranged in parallel within a single chip substrate, with shared inlet and outlet channels. This nesting allows compact integration of multiple measurement chambers while minimizing the overall sample volume required.
2Ease of manufacture
If fluid samples are removed and reused in the same cuvettes, then the per-test cost is reduced, but air-pockets may form during sample flow
Solution Approach 1:
The cuvettes are designed with curved, rounded corners and smooth transitions in the fluidic channels, eliminating sharp angles where air pockets could become trapped. The curved geometry facilitates complete sample evacuation and prevents air entrapment during sample removal and reuse cycles.
Solution Approach 2:
Air pockets are actively removed from the system through dedicated air-venting pathways and hydrophobic membrane structures that allow air to escape while preventing liquid leakage, enabling complete sample removal and reuse without air contamination.
3Measurement precision
If fluid samples are immobilized during measurement, then measurement accuracy and precision are improved, but additional valves and pressure control are required
Solution Approach 1:
A pressure control system uses pneumatic actuators to apply controlled pressure to fluidic channels, immobilizing samples in cuvettes during measurement. Pressure barriers are created to prevent sample displacement while maintaining simple valve structures integrated into the microfluidic chip.
Solution Approach 2:
The system dynamically adjusts pressure levels and valve states to immobilize samples only during measurement phases, while allowing free flow during sample introduction and removal phases. This dynamic control optimizes measurement precision without requiring permanent complex immobilization structures.
4Reliability
If cuvettes are designed to prevent air-pocket formation, then sample flow reliability is improved, but the cuvette geometry becomes more constrained
Solution Approach 1:
Cuvettes are designed with fully rounded corners and smooth curved transitions throughout the fluidic pathways, eliminating sharp angles and dead zones where air pockets could form. The curved geometry maintains reliable sample flow while accommodating standard photometric measurement requirements.
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
This solution allows for accurate and precise photometric measurements with reduced sample volume, lower costs, and the ability to perform multiple assays from a single sample, enhancing the efficiency and multiplexing capabilities of microfluidic systems.
Implementation Method 1
transmitting light from a first light source to a first photodetector through a corresponding first cuvette containing a first fluid sample
Implementation Method 2
having the at least one of the first and second fluid samples under pressure on a second side of the respectively-corresponding cuvette, where such pressure is formed by a second fluid in contact with the at least one of the first and second samples
Data Source
AI summary
Reusable network of spatially-multiplexed microfluidic channels each including an inlet, an outlet, and a cuvette in-between. Individual channels may operationally share a main or common output channel defining the network output and optionally leading to a disposable storage volume. Alternatively, multiple channels are structured to individually lead to the storage volume. An individual cuvette is dimensioned to substantially prevent the formation of air-bubbles during the fluid sample flow through the cuvette and, therefore, to be fully filled and fully emptied. The overall channel network is configured to spatially lock the fluidic sample by pressing such sample with a second fluid against a closed to substantially immobilize it to prevent drifting due to the change in ambient conditions during the measurement. Thereafter, the fluidic sample is flushed through the now-opened valve with continually-applied pressure of the second fluid. System and method for photometric measurements of multiple fluid samples employing such network of channels.