Flushable Test Strip with Ultrathin Hydrophobic Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional test strips for biochemical assays are not designed to dissolve in aqueous solutions, making them unsuitable for disposal through sewage systems, as they contain hydrophobic materials that prevent reagent mixing but do not break down quickly enough for efficient biodegradation.
Innovation Solution
A novel test strip with a water-soluble substrate layer and thin hydrophobic coating, featuring beveled reagent pads that absorb samples quickly and disintegrate in water, allowing for safe flushing through sewage systems without reagent cross-contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional hydrophobic materials are used to prevent reagent mixing on test strips, then reagent stability is improved, but biodegradability deteriorates
Solution Approach 1:
The patent changes the thickness parameter of the hydrophobic coating from traditional thick layers to an ultrathin configuration (approximately 0.1 to 2 micrometers). This parameter change allows the coating to maintain its reagent-blocking function during assay operation while enabling rapid disintegration and biodegradation during sewage processing, thus resolving the contradiction between reagent stability and biodegradability.
Solution Approach 2:
The patent applies different qualities to different parts of the test strip structure. The ultrathin hydrophobic coating provides localized reagent protection where needed (between reagent pads and substrate) while being sufficiently thin to allow rapid disintegration. This local quality differentiation enables the test strip to maintain reagent stability during use while achieving rapid biodegradation during disposal.
2Ease of manufacture
If ultrathin hydrophobic coating is used to enable rapid disintegration, then biodegradability is improved, but reagent protection deteriorates
Solution Approach 1:
The patent optimizes the thickness parameter of the hydrophobic coating to a specific range (0.1 to 2 micrometers) that balances two opposing requirements: being thin enough to allow rapid disintegration and biodegradation in sewage systems, while remaining thick enough to provide adequate protection against reagent mixing during the assay operation. This precise parameter control resolves the contradiction between reagent protection and biodegradability.
3Speed
If beveled cuts are used on reagent pads, then sample absorption speed is improved, but risk of pooling deteriorates
Solution Approach 1:
The patent introduces asymmetric beveled cuts on the reagent pads instead of traditional symmetric vertical cuts. The beveled surfaces create angled entry points that direct sample flow along the pad surface and into the absorbent material, preventing pooling while maintaining rapid absorption. This asymmetric geometry resolves the contradiction between absorption speed and pooling prevention.
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 test strip effectively dissolves and disperses in water, ensuring biodegradation and preventing reagent mixing, thus facilitating safe disposal through sewage systems while maintaining analytical functionality.
Implementation Method 1
The substrate layer may dissolve upon contact with water
Implementation Method 2
They typically include a layer of plastic of other hydrophobic material which will not break up in the sewer system. One purpose of the hydrophobic material is to keep the different reagents that are present on test trips from mixing when the test strip is exposed to a liquid sample
Implementation Method 3
The beveled cut results in sides that are angled toward the center of the strip and have more exposed cut fibers than would be present after a traditional vertical cut. These features may cause the liquid sample to absorb into the reagent pad more quickly
Implementation Method 4
Each reagent pad may include a different reagent which participates in a chemical reaction in the presence of a specific analyte. The product of the chemical reaction may be detectable through methods such as colorimetric or fluorescent spectrometry
Data Source
AI summary
We disclose a novel diagnostic test strip which may be used to conduct biochemical assays for analytes in liquid samples. The disclosed test strip may be loaded with much smaller volumes of sample than traditional test strips. The disclosed test strip may be loaded with a precision dispenser instead of submersing the test strip into a larger volume of liquid sample. In addition, the disclosed test strip dissolves in aqueous fluid so it may be flushed into the sewer system. Consequently, it is not necessary to dispose of the disclosed test strip in biological waste containers.