Metering Chamber Nozzle Design for Precise Reagent Dispensing
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Solution Overview
Problem
Existing fluid dispensing systems for biological sample processing face challenges in accurately dispensing predetermined amounts of reagents onto test slides, particularly in ensuring that all fluid is applied to the sample without excess remaining on the nozzle, which can affect sample treatment and lead to inconsistent results.
Innovation Solution
The fluid dispensing system incorporates a metering chamber with a deformable material and a liquid retention valve, coupled with a nozzle design that includes counter bores to capture excess fluid, ensuring precise control over the volume dispensed and minimizing fluid loss onto the nozzle surface, along with a compression assembly to regulate fluid ejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional nozzle design is used, then fluid dispensing is simple, but excess fluid remains on the nozzle surface leading to inconsistent sample treatment
Solution Approach 1:
The nozzle is divided into multiple functional segments: a main nozzle body and separate counterbore cavities. This segmentation allows each part to perform its specific function - the main nozzle dispenses fluid while the counterbores capture excess fluid, thereby improving dispensing precision without requiring complete redesign of the entire nozzle as a single complex component.
Solution Approach 2:
The counterbore cavities act as intermediary structures between the nozzle and the sample. These cavities serve as temporary holding zones for excess fluid, mediating the flow between the dispensing mechanism and the sample surface, preventing direct contact of excess fluid with the sample and ensuring consistent treatment.
2Quantity of substance
If fluid is dispensed onto the sample, then sample treatment is achieved, but fluid loss onto the nozzle surface occurs
Solution Approach 1:
The counterbore cavities convert the harmful effect of excess fluid on the nozzle surface into a beneficial feature. Instead of excess fluid being wasted or contaminating the sample, it is intentionally directed into the counterbore cavities where it is captured. This transforms fluid loss into a controlled containment mechanism, ensuring precise fluid volume delivery to the sample.
3Reliability
If a simple valve mechanism is used, then device operation is simple, but backflow and excess dispensing occur
Solution Approach 1:
The valve mechanism employs a flexible diaphragm or membrane that can deform to create fluid-tight seals. This flexible element responds to pressure changes and mechanical actuation, opening and closing the fluid passage as needed. The flexibility of the diaphragm allows it to conform to the valve seat, ensuring reliable sealing without requiring complex multi-component valve assemblies.
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 accurate and consistent dispensing of predetermined volumes of fluid onto biological samples, reducing waste and ensuring reliable sample treatment by effectively managing the 'last drop' of fluid and maintaining a fluid tight seal to prevent backflow and excess dispensing.
Implementation Method 1
a metering chamber (110) that extends from the fluid reservoir and is made of a deformable material
Implementation Method 2
a compression assembly to regulate ejection of the fluid onto the sample
Implementation Method 3
maintaining a fluid tight seal to prevent backflow and excess dispensing
Data Source
AI summary
An apparatus including a fluid reservoir and a compressible metering chamber including a first end coupled to the fluid reservoir and a second end. The apparatus further including a valve coupled to the second end of the metering chamber and a nozzle coupled to the valve. A system including linearly translatable cartridge mounting assembly having a plurality of fluid dispensing cartridge mounting stations and a plurality of fluid dispensing cartridges mounted to respective fluid dispensing cartridge mounting stations. The system further including a plurality of compression assemblies coupled to respective fluid dispensing cartridges and a receiving assembly positioned beneath the mounting assembly. A method includes positioning a fluid dispensing cartridge comprising a fluid reservoir and a metering chamber over a sample retaining member, applying a compressive force to the metering chamber to eject a predetermined amount of fluid and removing the compressive force to refill the metering chamber.