Micro Volume Inline Optical Sensor Asymmetric Flowcell Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inline optical sensors for biotechnology applications with smaller flow lines face issues such as drainage problems, liquid holdup, and air pockets in sample cavities, especially in low-pressure and low-flow conditions.
Innovation Solution
A micro volume inline optical sensor with a flowcell having a sample chamber that increases in diameter toward the middle, featuring monitoring ports with optically transmissive windows, mounting rings for light source and detector alignment, and controlled O-ring gasket compression for sealing, ensuring proper drainage and eliminating air pockets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the flowcell sample cavity volume is reduced to accommodate smaller flow lines (1/16 inch to 1/4 inch), then the sensor can be used in low-flow applications, but drainage problems and air pockets occur in the sample cavity
Solution Approach 1:
The sample cavity employs an asymmetric tapered design where the diameter increases from the downstream end toward the upstream end. This asymmetric geometry creates a slope that facilitates complete drainage of liquid from the cavity, preventing air pockets while maintaining a reduced overall volume suitable for small flow lines.
Solution Approach 2:
Instead of reducing the sample cavity to a simple small volume, the invention introduces a dimensional feature (taper along the optical path) that adds drainage functionality. The tapered shape creates a gradient in cross-sectional area along the length of the cavity, enabling gravity-assisted drainage without increasing the overall volume significantly.
2Reliability
If O-ring gaskets are compressed to ensure tight seals, then leakage is prevented, but the sealing force may damage the flowcell body or windows
Solution Approach 1:
The sealing system uses different compression forces at different locations. The first O-ring gasket (sealing the sample cavity) is compressed between the flowcell body and monitoring port, while the second O-ring gasket (sealing the mounting ring) is compressed between the mounting ring and flowcell body. This distributed local sealing approach prevents any single point from experiencing excessive stress.
Solution Approach 2:
The monitoring port structure acts as an intermediary element between the flowcell body and the external environment. It provides a dedicated sealing interface with O-ring gaskets that isolate the sealing function from the main flowcell body, preventing seal compression forces from directly stressing the optical windows or main structure.
3Ease of operation
If the flowcell is designed with vertical passageways for drainage, then liquid drainage is improved, but air pockets can still form in the sample cavity
Solution Approach 1:
The sample cavity employs an asymmetric tapered design where the diameter increases from the downstream end toward the upstream end. This asymmetric geometry creates a slope that facilitates complete drainage of liquid from the cavity, preventing air pockets while maintaining a reduced overall volume suitable for small flow lines.
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 provides a reliable, leak-proof inline optical sensor with a small sample chamber that effectively handles low-pressure and low-flow applications, ensuring accurate measurements by preventing air pockets and maintaining tight seals, suitable for use in high-temperature conditions.
Implementation Method 1
monitoring ports with optically transmissive windows at the ends of the chamber
Implementation Method 2
O-ring gaskets that surround the open ends and are compressed between the body of the flowcell and the windows
Data Source
AI summary
Micro volume inline optical sensor comprising a flowcell having a sample chamber which has a volume less than 0.4 mL and increases in diameter from two ends toward the middle, a flow passageway intersecting the chamber where the diameter is the greatest, monitoring ports with optically transmissive windows at the ends of the chamber, mounting rings on opposite sides of the flowcell disposed coaxially of an optical axis that passes through the monitoring ports and the sample chamber, and a light source and an optical detector mounted on the mounting rings in alignment with each other along the optical axis. In one embodiment, the sample chamber has a side wall with oppositely inclined frusto-conical sections, and the ends of the chamber are closed and sealed by the monitoring port windows and O-ring gaskets that surround the open ends and are compressed between the body of the flowcell and the windows.