Test Strip Cassette Optical Alignment via Spacer Structure
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Solution Overview
Problem
Existing test strip cassettes for lateral flow tests face challenges in sensitivity, multi-analyte detection, and complex assembly processes, limiting their effectiveness in home environments and point-of-care applications.
Innovation Solution
A test strip cassette design featuring a housing with a spacer structure that aligns a photodetector with a test strip's active area, allowing for efficient optical detection without the need for flip-chip bonding, and an external light source, enabling cost-effective fabrication and improved reproducibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If flip-chip bonding is used to attach the photodetector to the test strip, then the alignment precision is improved, but the manufacturing complexity increases
Solution Approach 1:
The photodetector is extracted from the test strip assembly and placed on a separate carrier. This eliminates the need for flip-chip bonding while maintaining alignment through the carrier's positioning structures, thereby reducing manufacturing complexity while preserving precision.
Solution Approach 2:
A carrier is introduced as an intermediary component between the photodetector and the test strip. The carrier includes positioning structures that mediate the alignment between the photodetector and the active area, eliminating the need for direct flip-chip bonding while ensuring precise alignment.
2Manufacturing precision
If an integrated housing with spacer structure is used, then the assembly precision is improved, but the device complexity increases
Solution Approach 1:
The housing and spacer structure are merged into a single integrated component. The spacer structure is formed as an integral part of the housing, eliminating the need for separate spacer components and reducing assembly steps while maintaining precise positioning.
Solution Approach 2:
The housing serves multiple functions: it provides structural enclosure, positioning for the test strip and carrier, and integrates the spacer structure for alignment. This multi-functionality reduces the number of separate components needed while maintaining assembly precision.
3Device complexity
If visual inspection is used for reading the test result, then the device simplicity is improved, but the measurement precision deteriorates
Solution Approach 1:
The mechanical/visual inspection method is replaced with an optical detection system using a photodetector. The photodetector automatically measures the optical signal from the active area, providing precise quantitative measurement while the integrated housing and carrier keep the device structure simple.
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 enhances the efficiency and reproducibility of light detection, simplifies the manufacturing process, and allows for accurate multi-analyte detection, making the test strip cassette more suitable for home and point-of-care use.
Implementation Method 1
The at least one photodetector, the at least one active area and the second opening are aligned with each other. Thus, an optical path is provided such that light can be transmitted through the second opening and the active area of the test strip.
Implementation Method 2
The carrier comprises at least one photodetector, the at least one photodetector being aligned with the second opening of the housing.
Implementation Method 3
The test strip comprises a sample pad aligned with the first opening and at least one active area aligned with the second opening and the at least one photodetector. The sample liquid flows using the capillary effect of the porous material.
Data Source
AI summary
A test strip cassette includes a housing defining a first opening being configured to receive a sample liquid, the housing further defining a second opening configured to provide an optical path into the housing, and a spacer structure. It further includes a carrier including at least one photodetector, the at least one photodetector being aligned with the second opening of the housing. It further includes a test strip including a sample pad aligned with the first opening and at least one active area aligned with the second opening and the at least one photodetector. The housing encloses the carrier and the test strip, such that the test strip is spaced from the carrier by the spacer structure and arranged between the second opening and the carrier.