Chip-Based Optical Detection System Using Diffusion-Dominated Mixing
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Solution Overview
Problem
Existing optical target detection systems face challenges in efficiently processing liquid samples due to complex fluid dynamics, high costs, and reduced sensitivity caused by non-specific binding of analytes to channel walls.
Innovation Solution
A chip-based optical detection system with a diffusion-dominated assay configuration, where capture components and detection reagents are placed within a diffusion distance of each other, eliminating the need for premixing and allowing for simultaneous interaction with the sample.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If detection reagents and capture components are placed close together within diffusion distance, then the footprint of the detection system is reduced, but the mixing efficiency may be compromised
Solution Approach 1:
The patent replaces mechanical mixing systems (pumps, channels, flow control mechanisms) with a diffusion-dominated mixing approach. By positioning detection reagents and capture components within diffusion distance of each other, the system allows molecular diffusion to achieve mixing without requiring complex fluid dynamics control, thereby reducing the device footprint while maintaining mixing efficiency.
Solution Approach 2:
The patent transitions from three-dimensional flow-based mixing to a two-dimensional diffusion-based approach by placing reagents and capture components in close proximity within the same plane or layer. This dimensional simplification eliminates the need for extended flow channels and mixing chambers, reducing the overall device area while enabling efficient reagent-sample interaction through diffusion.
2Speed
If bulk flow dominated regimen is used, then the liquid sample can be transported quickly through the cartridge, but the signal becomes dependent on flow speed and directionality
Solution Approach 1:
The patent employs a dynamic flow regime that transitions from bulk flow (for rapid sample transport) to diffusion-dominated flow (for reliable signal generation). The system allows the liquid sample to flow quickly through the cartridge initially, then slows down or stops near the detection zone where diffusion predominates, ensuring that the signal becomes independent of flow speed and directionality while maintaining efficient transport.
Solution Approach 2:
The patent implements a periodic or staged flow pattern where the liquid sample is first introduced at relatively rapid flow rates for quick transport, then the flow is reduced or halted to allow diffusion-dominated interaction between the sample, detection reagents, and capture components. This staged approach ensures both rapid sample delivery and reliable signal generation independent of flow conditions.
3Ease of operation
If channels and pumps are used for introducing reagent, then the reagent can be delivered to the sample, but the design complexity and fabrication cost increase
Solution Approach 1:
The patent extracts or eliminates the need for complex pump and channel systems by placing detection reagents directly within the diffusion distance of capture components in a simplified cartridge architecture. Reagent delivery is achieved through passive diffusion and simple fluid flow paths without requiring active pumping mechanisms or complex channel networks, thereby reducing design and fabrication complexity while maintaining reagent delivery capability.
Solution Approach 2:
The patent enables the assay system to self-deliver reagents through diffusion-dominated transport without requiring external pumps or complex flow control mechanisms. The detection reagents are positioned such that they can interact with the sample and capture components through natural diffusion processes, allowing the system to function with minimal mechanical assistance and reduced structural complexity.
4Reliability
If premixing of detection reagents and sample is required, then the assay can proceed, but the process time and device footprint increase
Solution Approach 1:
The patent performs preliminary positioning of detection reagents and capture components within diffusion distance of each other before sample introduction. This pre-arranged configuration eliminates the need for time-consuming premixing steps, as the reagents are already in optimal positions to interact with the sample through diffusion once introduced, thereby reducing process time while maintaining assay performance.
Solution Approach 2:
The patent merges the sample introduction step with the mixing step by allowing the liquid sample to directly contact both detection reagents and capture components simultaneously as it flows through the cartridge. This consolidation eliminates separate premixing operations, reducing process time and simplifying the assay workflow while ensuring reliable interaction between all components.
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 configuration enhances assay performance by reducing the footprint of the detection system, minimizing nonspecific binding, and providing a reliable, cost-effective method for detecting target components in liquid samples.
Implementation Method 1
Once the liquid sample reaches the vicinity of the capture components and detection reagents, its velocity is drastically reduced so that diffusion predominates. The capture components and detection reagents are provided within the diffusion distance and therefore they can combine with the sample without any need for premixing.
Implementation Method 2
Chip-based optical detection system for detecting a target component in a liquid sample
Data Source
AI summary
A chip-based optical detection system for detecting a target component in a liquid sample is provided. The system comprises a fluid pathway disposed in an interior volume of the chip; an inlet fluidically connecting an external surface of the chip to the fluid pathway; an optical element at least partially defining the fluid pathway; and a flow controller configured to control a flow of the liquid sample through the fluid pathway. One or more capture components are immobilised on the optical element, one or more detection reagents are provided in a proximity of the capture components, and the flow controller is configured to control the flow of the liquid sample along the fluid pathway such that the detection reagents are brought into contact with the capture components via diffusion.