Microfluidic Device Tapered Coupling Zone Air-Bubble Prevention
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Solution Overview
Problem
Microfluidic devices face instability in liquid-feeding due to air-bubble formation in the coupling portion, which disrupts uniform flow and affects detection sensitivity.
Innovation Solution
A microfluidic device design featuring a main channel with a tapered coupling zone and pair of branch channels connected across the main channel, where the branch channels have a deeper bottom and shallower ceiling than the main channel, preventing air-bubbles from forming along the edges and ensuring stable liquid-feeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the microchannel thickness is reduced at the detection portion to enhance sensitivity, then detection sensitivity is improved, but air-bubbles are generated in the coupling portion disrupting flow stability
Solution Approach 1:
The microchannel is divided into three distinct zones: a first zone with larger thickness, a second zone with smaller thickness, and a coupling zone connecting them. The coupling zone is further segmented with multiple connection zones that overlap with the tapering region, creating a structured transition that prevents air-bubble entrapment while maintaining the thickness reduction needed for sensitivity.
Solution Approach 2:
Different portions of the microchannel are given different thickness characteristics: the first zone has larger thickness for stable liquid feeding, the second zone has smaller thickness for enhanced detection sensitivity, and the coupling zone has gradually decreasing thickness to bridge the two. This local differentiation allows each zone to optimize its function without compromising the other.
2Productivity
If the microchannel thickness is reduced at the detection portion, then electrode active material action is facilitated, but air-bubble formation occurs in the tapered coupling portion
Solution Approach 1:
The coupling zone is designed with a gradual thickness decrease before the liquid reaches the thin detection portion. This preliminary tapering action allows the liquid to adapt to the changing cross-section smoothly, preventing air-bubble formation that would otherwise occur at abrupt transitions. The connection zones are positioned to overlap with this tapering region, further ensuring smooth transition.
3Stability of the object's composition
If a tapered coupling portion is used to connect zones of different thickness, then liquid flow transition is improved, but air-bubbles are still trapped along the edges
Solution Approach 1:
The connection zones are positioned in the width direction of the microchannel, creating a three-dimensional overlapping structure. This dimensional approach allows the liquid to transition through the coupling zone from multiple pathways, preventing air-bubbles from being trapped along the edges while maintaining flow uniformity. The overlap in the width direction provides redundant flow paths that eliminate dead zones where bubbles could accumulate.
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 prevents air-bubble entrapment, stabilizes liquid flow, and enhances detection sensitivity by ensuring uniform liquid distribution across the microchannel.
Implementation Method 1
A sample subjected to a pretreatment to link a predetermined enzyme to allergen is caused to flow in the microchannel 105
Implementation Method 2
The substrate-material contained in the buffer solution is changed in a process, in which the buffer solution flows in the reaction portion 106, into an electrode active material by the enzyme linked to the allergen trapped in the reaction portion 106
Implementation Method 3
The electrode active material reaches the detection portion 107 and acts upon the electrode 109 to thereby generate electric current
Implementation Method 4
Allergen contained in the sample is trapped by the antibody fixed in the reaction portion 106
Data Source
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AI summary
It is a microfluidic device including a flowchannel in which liquid flows. The flowchannel includes a main channel and a pair of branch channels provided across the main channel from each other to be each connected to the main channel. The main channel includes a first zone, a second zone, and a coupling zone that connects the first zone and the second zone. The second zone is smaller than the first zone in a distance between a bottom surface and a ceiling surface. The coupling zone is configured such that the distance between the bottom surface and the ceiling surface thereof gradually decreases towards the second zone from the first zone. A connection zone provided in the main channel and connected to each of the pair of branch channels overlaps with the coupling zone.