Microfluidic Cartridge Air-Flow Inspection for Seal and Valve Alignment
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Solution Overview
Problem
Microfluidic devices face issues with unreliable seals between the instrument, flowcell, and cartridge, leading to failed runs and potential damage due to liquid leakage, as well as challenges in accurately establishing the home position of the rotary valve, which affects the alignment and functionality of reagents.
Innovation Solution
An in-situ inspection method using a flow sensor and pressurized air to test the integrity of seals between the instrument and cartridge components, including the rotary valve, flowcell, and pinch valves, while also determining the home position of the rotary valve with high accuracy and correcting for hysteresis or backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional seal inspection methods are used, then manufacturing time is reduced, but seal reliability deteriorates leading to failed runs and liquid leakage
Solution Approach 1:
The patent performs seal integrity testing and home position verification as preliminary actions before actual microfluidic operations. The system automatically conducts these inspections when the cartridge is first inserted, identifying and isolating defective seals or misaligned rotary valves before they cause failed runs or liquid leakage, thereby preventing waste of subsequent reagents and operations.
Solution Approach 2:
The system uses its own operational components (pumps, valves, flow sensors) to perform self-diagnosis of seal integrity and alignment. The cartridge's existing fluidic pathways are utilized for testing without requiring separate external inspection equipment, enabling the system to verify its own functionality and automatically compensate for detected issues.
2Measurement precision
If rotary valve alignment is not accurately established, then device complexity is reduced, but measurement precision deteriorates affecting reagent flow control
Solution Approach 1:
The system employs feedback mechanisms where flow sensors monitor actual reagent flow through the rotary valve at different angular positions. By measuring flow rates and detecting maximum flow points, the system automatically determines the precise home position of the rotary valve and adjusts alignment accordingly, achieving high measurement precision through iterative feedback rather than complex mechanical alignment features.
Solution Approach 2:
The patent replaces complex mechanical alignment mechanisms with fluid-based sensing and control. Instead of using精密 mechanical features to ensure rotary valve alignment, the system uses flow sensors to detect alignment status and employs software-controlled adjustments, substituting mechanical complexity with sensor-based detection and computational correction.
3Reliability
If in-situ inspection is performed, then reliability is improved, but device complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The patent makes existing components multi-functional by enabling them to serve both operational and inspection purposes. The pumps, valves, and flow sensors used during normal microfluidic operations are also utilized for conducting seal integrity tests and home position verification. This eliminates the need for separate dedicated inspection hardware, maintaining reliability improvement while minimizing increases in device complexity.
Solution Approach 2:
The inspection system leverages the cartridge's own operational components to perform self-diagnosis. The fluidic pathways, pumps, and sensors already present for normal operation are repurposed to conduct integrity testing, allowing the system to verify its own functionality without requiring external inspection equipment or adding significant complexity to the device architecture.
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 method effectively verifies the integrity of fluidic seals and accurately establishes the home position of the rotary valve, ensuring reliable operation and preventing damage from leakage, thereby enhancing the functionality and reliability of microfluidic devices.
Implementation Method 1
A source of pressurized air is connected to the flow sensor to establish a mass flow of air through a flow path. The mass flow of air through the flow path is measured with the flow sensor.
Implementation Method 2
A source of pressurized air is connected to the flow sensor to establish a mass flow of air through a flow path.
Data Source
AI summary
A method includes engaging a well of a cartridge with a flow sensor of an instrument. The cartridge includes: a rotary valve including a rotatable port and a center port; the well in fluid communication with a channel, the channel including a channel port that the rotatable port is to align to in order to receive fluid from the well; and a flowcell including an inlet gasket in fluid communication with the center port. A source of pressurized air is connected to the flow sensor in order to establish a mass flow of air through a flow path. The flow path extends through one of the flow sensor, the channel, the rotary valve, and the flowcell. The mass flow of air through the flow path is measured with the flow sensor. It is determined if there is one of an air leak and an air blockage within the flow path.