Microfluidic Chip Asymmetric Flow Path Resistance
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Solution Overview
Problem
Existing chip designs for fluid merging in tests and analyses face challenges in accurately controlling the discharge amount of liquid delivery pumps, leading to potential air bubble entrainment and increased manufacturing costs due to the need for large-scale devices.
Innovation Solution
The chip design incorporates a flow path structure with specific resistance characteristics, including a merging portion, connection flow paths with varying resistances, and a degassing flow path, which allows for the suppression of air bubble entrainment without requiring high-accuracy discharge control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If surface treatment is applied to micro flow paths to align fluid delivery timing, then timing alignment is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent changes the physical parameters of the flow paths by creating asymmetric path lengths and resistance characteristics. The first flow path has a longer path length than the second flow path, and connection flow paths are introduced with specific resistance values to compensate for timing differences without requiring surface treatment. This achieves timing alignment through geometric parameter adjustment rather than surface modification.
2Manufacturing precision
If liquid delivery pump discharge amount is controlled with high accuracy, then fluid merging precision is improved, but device size increases
Solution Approach 1:
The system uses the inherent resistance characteristics of the flow paths to automatically regulate fluid delivery. The connection flow paths have higher resistance than the main flow paths, creating a pressure differential that self-regulates the timing and amount of fluid merging. This eliminates the need for high-precision pump control mechanisms, allowing the use of simpler, more compact pumping systems.
3Manufacturing precision
If liquid delivery pump discharge amount is controlled with high accuracy, then fluid merging precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent achieves precise fluid merging by changing the resistance parameters of the connection flow paths. The connection flow paths are designed with higher resistance than the main flow paths, which creates a pressure differential that naturally synchronizes fluid delivery timing. This parameter-based approach replaces the need for expensive high-precision pump control systems, significantly reducing manufacturing costs while maintaining merging precision.
4Manufacturing precision
If connection flow paths with higher resistance are introduced, then timing synchronization is improved, but liquid delivery efficiency decreases
Solution Approach 1:
The patent applies different resistance characteristics to different parts of the flow path system. The connection flow paths have higher resistance to achieve timing synchronization, while the main flow paths maintain lower resistance for efficient bulk fluid transport. This localized differentiation of flow path properties allows the system to achieve both timing precision and delivery efficiency simultaneously.
Data Source
AI summary
A chip that does not require high-accuracy discharge amount control for a liquid delivery pump and can suppress entrainment of air bubbles, including: a first flow path; a second flow path; a merging portion provided on a downstream end portion side of the first flow path and merge the first fluid and the second fluid; a first connection flow path connecting the first flow path and the second flow path at the merging portion and have a liquid delivery resistance higher than the first flow path; a degassing flow path connecting to the second flow path on a downstream side of the first connection flow path; a third flow path provided on a downstream side of the merging portion; and a second connection flow path connecting the first flow path and the third flow path and have a liquid delivery resistance higher than the first flow path.