Centrifugal Liquid Router with Hydrophobic Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid routers in centrifugally based microfluidic devices lack the ability to freely switch between exit microconduits in a controlled and regulated manner without the need for electricity or movable parts, and they are not robust enough to support parallel operation of multiple microchannel structures.
Innovation Solution
A liquid router design that incorporates a microcavity with two exit openings and an inlet opening, where one exit microconduit has reduced hydrophilicity due to hydrophobic patterning, allowing liquid flow to be controlled by spin speed, enabling switching between microconduits and supporting parallel operation of multiple microchannel structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a liquid router uses a simple branched inlet microconduit design, then the device complexity is reduced, but the ability to freely switch between exit microconduits in a controlled manner is lost
Solution Approach 1:
The patent applies local quality by creating asymmetric surface properties in different parts of the microconduit system. Specifically, one exit microconduit has a hydrophobized section while the other has a hydrophilic section, allowing the liquid flow to be directed to different exits based on wettability differences without adding mechanical complexity to the overall router structure
Solution Approach 2:
The patent changes the surface energy parameter of the microconduit walls through hydrophobization treatment. By modifying the surface characteristics (wettability) of specific sections, the system enables controlled switching of liquid flow between exit microconduits based on centrifugal force and surface energy differences, achieving adaptability without mechanical components
2Productivity
If a liquid router is designed for reliable switching between exit microconduits, then the productivity is improved, but the device complexity increases due to additional surface treatment requirements
Solution Approach 1:
The patent replaces mechanical switching mechanisms with a surface energy-based routing system. Instead of using movable parts or complex mechanical valves to direct liquid flow, the system uses differences in surface wettability (hydrophobic vs. hydrophilic sections) combined with centrifugal force to achieve controlled switching, thereby improving productivity without adding mechanical complexity
Solution Approach 2:
The liquid flow routing is achieved through self-service mechanisms where the liquid's own surface tension and interaction with the hydrophobic/hydrophilic surfaces determine its path. The system automatically directs flow to the appropriate exit microconduit based on the balance between centrifugal force and surface energy, eliminating the need for external control mechanisms
3Reliability
If a liquid router uses hydrophobic patterning to control flow, then the reliability of switching is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent segments the microconduit system into distinct functional zones with different surface properties. The inlet microconduit, exit microconduits, and intermediate sections are divided into hydrophobic and hydrophilic segments, allowing reliable flow control through clear spatial separation of surface energy characteristics. This segmentation approach enhances switching reliability while providing tolerance in manufacturing by creating distinct functional regions
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
Enables reliable and controlled switching of liquid flow between microconduits based on spin speed, enhancing the robustness and parallel operation capabilities of microfluidic devices, reducing the need for complex mechanisms and improving process efficiency.
Implementation Method 1
a liquid router (1) that comprises an inlet microconduit (3) that branches into two exit microconduits (microconduit I and II, (4 and 5, respectively)) and is present in a microchannel structure (6) of a microfluidic device (7) which is using centrifugal force created by spinning the device (7) around a spin axis (8a) for transporting liquid
Implementation Method 2
a non-wettable patch (28) on the inner surface (17) between the inlet opening (14) and exit I (12). The patch (28) is capable of hindering liquid transport on the surface (17) from the inlet opening (14) to exit I (12)
Data Source
AI summary
A liquid router that comprises an inlet microconduit that branches into two exit microconduits (microconduit I and II) and is present in a microchannel structure of a microfluidic device which is using centrifugal force created by spinning the device about a spin axis for transporting liquid. The router is characterized in comprising a microcavity in which there are: a lower part comprising two exit openings (exits I and II), and an upper part comprising an inlet opening to which the inlet microconduit (3) is connected, and microconduits I and II which are connected to exits I and II, respectively, and stretch from a shorter radial position to a larger radial position relative to the spin axis. Microconduit II has a reduced hydrophilicity (=reduced apparent wettability) compared to microconduit I.