Microfluidic Device With Segmented Porous Membranes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microfluidic devices face issues with sample fluid leakage through porous membranes and are vulnerable to mechanical stress, limiting their robustness and manufacturing complexity, especially when handling small sample volumes and viscous samples.
Innovation Solution
The design incorporates non-interconnected membranes with porous material integrated within recesses, providing robustness and reduced leakage, allowing for increased pressure and flow speed, and using substrates with alternating porous and solid areas to enhance mechanical strength and manufacturing simplicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If porous membranes are used in microfluidic devices to enable flow-through concept, then efficient capturing of target substance is accomplished due to small diffusion distances, but sample fluid leakage occurs through the porous membrane from one recess to another recess via paths not part of the channel
Solution Approach 1:
The device divides the porous membrane into separate segments by introducing solid walls between adjacent recesses. These walls prevent lateral fluid flow between recesses while maintaining the flow-through capability of individual membrane sections, thus eliminating leakage without compromising capturing efficiency
Solution Approach 2:
Solid walls are introduced as intermediary structures between adjacent porous membrane regions. These walls act as barriers that block unwanted lateral fluid transport while allowing the porous membranes to maintain their primary function of efficient target substance capturing through small diffusion distances
2Reliability
If porous material is used in recesses to support and protect from destruction, then robustness and reliability are improved, but manufacturing complexity increases due to the need for precise positioning and integration
Solution Approach 1:
The porous material is integrated directly into the recesses of the substrate, merging the support function with the structural component. This integration provides mechanical protection and robustness while simplifying the overall device architecture and manufacturing process by eliminating separate support structures
Solution Approach 2:
Porous material is used to fill the recesses, providing both mechanical support and protection from destruction. The porous structure maintains robustness and reliability while allowing fluid flow, and its integration into the recesses simplifies manufacturing compared to separate component assembly
3Ease of manufacture
If membranes are made thinner to improve handling and manufacturing efficiency, then ease of manufacture is improved, but mechanical strength decreases making them more vulnerable to mechanical stress
Solution Approach 1:
The thin porous membranes are nested within recesses in the substrate, where they are supported and protected by the surrounding solid material. This nesting arrangement allows the use of thinner membranes that are easier to handle and manufacture while the substrate structure provides the necessary mechanical strength and protection
Solution Approach 2:
The device uses a composite structure combining thin porous membranes with solid substrate material. The porous membrane provides the necessary flow characteristics and is easier to handle, while the solid substrate provides mechanical strength and protection, creating a synergistic composite structure that achieves both ease of manufacture and structural integrity
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 sample fluid leakage, increases the robustness and reliability of the device, enables faster operation, and allows for the use of thinner, more brittle membranes, improving handling and manufacturing efficiency while maintaining sensitivity and reliability in detecting target substances.
Implementation Method 1
By forcing the sample fluid through the membrane, the diffusion distances become very small for the biological molecules comprised in the sample fluid, so that diffusive transport will not limit the adsorption kinetics
Implementation Method 2
the target substance is bound or captured by a capture substance that is immobilized on a surface within a micro fluidic device
Data Source
Figure 1~3
Figure 4~5
Figure 6A~6D
AI summary
The present invention provides a microf luidic device, for instance for molecular sieving or for detecting a target substance in a sample fluid. The device comprises a first substrate (120) having a substantially flat first surface that is provided with first recesses (124), and a second substrate (128) having a substantially flat second surface that is provided with second recesses (130). At least some of the first recesses are filled with a porous material (114). Alternate first recesses and second recesses form a meandering channel for a sample fluid. The second recesses may be filled with a further porous material. In an embodiment, a capture substance for binding a target substance is arranged in or on the porous material.