Biochemical Cartridge Elastic Membrane Flow Control
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Solution Overview
Problem
Existing methods for controlling the flow of reagents and samples in microdevices face challenges in preventing contamination by suspended DNA in air and accurately controlling fluid flow parameters such as flow amount and flow time.
Innovation Solution
A disposable biochemical cartridge with sealed chambers and an elastic membrane that forms a flow path only upon deformation, coupled with a cartridge holder that applies air pressure to activate the membrane as a pump mechanism, allowing for controlled liquid flow without direct contact with ambient air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pipetting technique using a dispenser robot is used to mix reagents, then reagents can be delivered to cells for biochemical processes, but contamination by suspended DNA in air cannot be prevented
Solution Approach 1:
The device is divided into multiple sealed chambers (first chamber for reagent storage, second chamber for sample processing, third chamber for PCR) that are physically separated by a partition wall. This segmentation prevents suspended DNA in air from contaminating the sample and reagent interfaces, while still allowing controlled reagent delivery through the sealed partition wall structure.
Solution Approach 2:
The chambers are sealed to create isolated environments that prevent interaction with ambient air containing suspended DNA. The first chamber is sealed with a first seal, the second chamber with a second seal, and the partition wall itself acts as a sealed barrier, creating inert environments that protect against contamination while maintaining operational functionality.
2Reliability
If chambers are sealed inside a cartridge main body with an elastic membrane, then liquid flow can be controlled in isolation from ambient air, but the flow path is not formed until the membrane is deformed
Solution Approach 1:
The partition wall incorporates an elastic membrane that dynamically changes from a non-flow state to a flow state through deformation. The membrane remains intact and sealed during storage, then deforms upon application of external force (such as pressure from a syringe or pump) to create a flow path. This dynamic transformation allows the system to maintain reliability during storage while enabling controlled liquid flow during operation.
Solution Approach 2:
The elastic membrane is pre-positioned in a sealed configuration within the partition wall before use. The sealing structure and membrane arrangement are prepared in advance to ensure no flow paths exist during storage and transport. When operation begins, the pre-positioned membrane is deformed to create the flow path, ensuring that contamination prevention is maintained until the moment flow is intentionally initiated.
3Speed
If centrifugation technique or direct air pressure enclosure is used to send liquid, then liquid can be moved inside a microdevice, but contamination by suspended DNA in air may still occur and flow control is difficult
Solution Approach 1:
The device separates liquid storage and transport functions into sealed chambers (first chamber for reagent, second chamber for sample) divided by a sealed partition wall. This segmentation allows liquid to be transported within the sealed environment using centrifugation or pressure differential, preventing suspended DNA in ambient air from contaminating the liquid, while maintaining efficient liquid movement through the separated but connected chamber system.
Solution Approach 2:
The sealed chambers create isolated inert environments that protect the liquid from contamination by suspended DNA in air during transport. The first seal and second seal maintain these inert environments, allowing centrifugation or pressure-driven liquid flow to occur within the protected sealed system without exposure to contaminating airborne particles.
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 enables precise control of fluid flow within a sealed environment, minimizing contamination risks and improving the reliability of biochemical processes by ensuring reagents are sent at appropriate timings and amounts, thus enhancing the accuracy of chemical reactions and analyses.
Implementation Method 1
an elastic body membrane is attached to the bottom surface of the cartridge main body. The membrane is not bonded to a portion that becomes a flow path between the chambers, and a flow path is formed only after the membrane is deformed in the unbonded portion. Membrane deformation also provides a pump function that varies the volume of the flow path with the reciprocal movement of the membrane in response to changes in externally applied pressure.
Implementation Method 2
a flow path is formed only after the membrane is deformed in the unbonded portion. Membrane deformation also provides a pump function that varies the volume of the flow path with the reciprocal movement of the membrane in response to changes in externally applied pressure.
Data Source
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AI summary
A cartridge sealed from ambient air is used to send a liquid without causing the liquid to contact the fluid inside the cartridge. This enables the reagents to be processed such as by being mixed, agitated, purified, and reacted while preventing contamination with suspended DNA in air. The cartridge has a simple structure to reduce the cost of the cartridge itself. Inside of the cartridge 1 sealed from ambient air are provided chambers that send and receive reagents, and an elastic body membrane 51 is attached to the bottom surface. The cartridge main body 51 does not have a groove or anything else that becomes a channel, and the membrane 51 is not bonded to portions that become channels. A channel, not formed in a normal state, is formed upon deforming the membrane 51 under air pressure in the unbonded portion, and the fluid is moved inside. A valve function is provided at an inlet of each chamber, and the fluid is internally moved in any direction with channel deformation.