Inlaid Optical Cell for Microfluidic Spectroscopy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microfluidic optical cells face challenges in mechanical stability and alignment during manufacturing, leading to reduced optical coupling and measurement errors, especially when transitioning from laboratory to field environments, and require complex alignment processes using epoxies which are tedious and prone to errors.
Innovation Solution
An optical cell design featuring an inlaid sheet with opaque and clear materials, where the opaque material has 0% light transmittance and the clear material has greater than 90% light transmittance, allowing for integrated optical windows and prisms to isolate light transmission within the sensing channel, eliminating the need for epoxies and enabling robust and repeatable alignment through standard manufacturing practices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If fiber-based designs are used to couple light to/from a flow cell, then optical coupling can be achieved, but mechanical stability is reduced due to sensitivity to shocks and vibrations
Solution Approach 1:
The patent integrates the optical coupling mechanism directly into the chip structure by forming optical windows through the substrate, eliminating the need for separate fiber optic components. This merging of functions creates a more robust system that maintains optical coupling without the mechanical fragility of fiber-based designs.
2Ease of manufacture
If completely integrated absorbance cell in chips is used, then manufacturing robustness is improved, but alignment precision deteriorates requiring epoxy fixation
Solution Approach 1:
The patent pre-forms optical windows directly into the chip substrate during the manufacturing process, establishing precise optical pathways before component assembly. This preliminary action eliminates the need for post-manufacturing alignment and epoxy fixation, achieving both manufacturing robustness and alignment precision.
3Manufacturing precision
If epoxy fixation is used to hold LED and photodiode in alignment, then alignment precision is improved, but device complexity increases due to additional materials and processes
Solution Approach 1:
The patent extracts and eliminates the epoxy fixation step from the manufacturing process by integrating optical windows directly into the substrate. This removal of unnecessary materials and processes simplifies the fabrication workflow while maintaining precise optical alignment through the pre-formed window structures.
4Manufacturing precision
If skilled workflow with measurements is used during manufacturing, then alignment precision is improved, but productivity decreases due to tedious processes
Solution Approach 1:
The patent designs the chip substrate to self-align optical components through pre-formed optical windows that guide light paths inherently. This self-aligning mechanism eliminates the need for skilled manual measurement and adjustment workflows, enabling automated manufacturing processes that significantly improve productivity while maintaining precision.
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 enhances the manufacturability and reliability of microfluidic optical cells by minimizing background light interference, allowing for flexible light source and detector combinations, and providing accurate absorbance, fluorescence, and scattering measurements without the need for complex alignment processes, making them suitable for field applications.
Implementation Method 1
a sensing channel having first and second ends and providing a fluidic path for the liquid sample and an optical path for probe light between the first and second ends
Implementation Method 2
an inlaid sheet comprising an opaque material inlaid within a clear material
Data Source
AI summary
An optical cell for performing light spectroscopy (including absorbance, fluorescence and scattering measurements) on a liquid sample in microfluidic devices is disclosed. The optical cell comprises an inlaid sheet having an opaque material inlaid in a clear material, and a sensing channel that crosses the clear material and the opaque material provides a fluidic path for the liquid sample and an optical path for probe light. Integral optical windows crossing a clear-opaque material interface permit light coupling into and out of the sensing channel, and thus light transmission through the sensing channel is almost entirely isolated from background light interference. A microfluidic chip comprising one or more optical cells is also disclosed. The optical cells may have different lengths of sensing channels, and may be optically and fluidly coupled. A method of manufacturing an optical cell in a microfluidic chip is also disclosed.