Flow Cell Cuvette Geometry for Stray Light Suppression
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Solution Overview
Problem
Precise detection of a fluidic sample in a sample separation apparatus is difficult due to undesired stray radiation that increases background noise and overlays artifacts in the detection signal.
Innovation Solution
A flow cell design with a cuvette geometry configured to keep at least one point at the excitation backside surface and/or edge at the emission backside surface outside the direct field of view of the electromagnetic radiation outlet, combined with an electromagnetic radiation absorber on the excitation backside surface to suppress stray light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional cuvette geometry is used, then the device complexity is low, but stray radiation increases background noise and reduces measurement precision
Solution Approach 1:
The patent applies asymmetry by configuring the cuvette with non-symmetric features including a beveled edge at the excitation backside surface and asymmetric positioning of the flow channel relative to the cuvette walls. This asymmetric geometry prevents stray radiation from reflecting off symmetric surfaces back into the detection path, thereby reducing background noise while maintaining a manufacturable design
Solution Approach 2:
The patent introduces a new dimensional element by adding a beveled surface at the excitation backside of the cuvette. This angular feature creates a third spatial dimension for radiation control, directing stray light away from the detection path through geometric optimization rather than requiring additional absorbing materials or complex multi-layer structures
2Measurement precision
If the cuvette is configured to reduce stray light, then measurement precision improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent optimizes specific geometric parameters of the cuvette including the bevel angle (optimized to redirect stray light away from the detection path), the flow channel dimensions and positioning, and the wall thicknesses. These parameter optimizations achieve effective stray light reduction while establishing practical tolerance ranges that can be met by standard manufacturing processes
3Object-affected harmful factors
If electromagnetic radiation absorber is added to the excitation backside surface, then stray light is suppressed, but device complexity increases
Solution Approach 1:
The patent applies local quality by selectively applying electromagnetic radiation absorbing material only to the excitation backside surface of the cuvette, specifically in regions where stray radiation is most problematic. This localized treatment targets the harmful effect precisely where it originates without requiring absorption materials throughout the entire flow cell structure
Solution Approach 2:
The electromagnetic radiation absorber acts as an intermediary element between the excitation source and the detection path. By placing absorbing material at the excitation backside surface, the patent creates an intermediate layer that intercepts and absorbs stray radiation before it can reflect into the detection path, thereby protecting the measurement system without requiring direct modification of the detection optics
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 design significantly reduces stray light propagation, enhancing the signal-to-noise ratio and improving the accuracy of fluidic sample detection.
Implementation Method 1
an electromagnetic radiation inlet at which an excitation electromagnetic radiation beam is couplable into the cuvette, and an electromagnetic radiation outlet at which an emission electromagnetic radiation beam, generated by an interaction between the excitation electromagnetic radiation beam and the separated fluidic sample
Implementation Method 2
combined with an electromagnetic radiation absorber on the excitation backside surface to suppress stray light
Implementation Method 3
an emission electromagnetic radiation beam, generated by an interaction between the excitation electromagnetic radiation beam and the separated fluidic sample
Data Source
AI summary
A flow cell, for detecting a fluidic sample separated by a sample separation apparatus, includes a cuvette, a flow channel formed at least partially in the cuvette and configured to enable a flow of the separated fluidic sample through the flow channel, an electromagnetic radiation inlet at which an excitation electromagnetic radiation beam is couplable into the cuvette, and an electromagnetic radiation outlet at which an emission electromagnetic radiation beam, generated by an interaction between the excitation electromagnetic radiation beam and the separated fluidic sample, is couplable out of the cuvette. A geometry of the cuvette is configured so that at least one point at the excitation backside surface of the cuvette is outside of a direct field of view of the electromagnetic radiation outlet.