Deflectable Valve Microfluidic Network for Cross-Contamination Prevention
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Solution Overview
Problem
Existing microfluidic network devices face challenges with cross-contamination and dead volumes, lack versatility, and are not suitable for efficient reagent delivery and mixing, particularly in cartridge-based systems with pneumatic actuation.
Innovation Solution
A microfluidic network device with deflectable valves that interconnect multiple inlet channels to a common outlet channel, featuring a valve structure with a deflectable member that prevents backflow and cross-contamination, and includes a mixing network for efficient reagent mixing and delivery, utilizing pneumatic or hydraulic actuation to control fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a normally closed valve structure with pneumatic actuation is used, then the valve can control fluid flow, but back flow and cross contamination between reagents occurs
Solution Approach 1:
The patent inverts the conventional normally closed valve structure by implementing a normally open valve configuration. The valve remains open by default and closes only when pneumatic pressure is applied, eliminating back flow and cross-contamination risks while maintaining reliable flow control for multiple reagents
Solution Approach 2:
The patent introduces an intermediary pneumatic actuation mechanism that mediates between the fluid flow control and the valve positioning. This pneumatic system provides precise control over when the valve closes, enabling reliable reagent delivery without cross-contamination by ensuring the valve remains open during normal flow operations
2Manufacturing precision
If a single reservoir system with pre-determined volume delivery is used, then the device can deliver fixed volumes, but it lacks versatility and is suitable only for specific applications
Solution Approach 1:
The patent implements a universal valve system that can control multiple reagent reservoirs with different volumes and types. The normally open valve configuration works across all reservoirs, enabling the same device structure to serve multiple applications including but not limited to nucleic acid preparation, protein analysis, and other biochemical assays
Solution Approach 2:
The patent introduces dynamic control of the valve timing and duration to accommodate different reagent delivery requirements. By controlling how long the valve remains open and when it closes, the system can deliver varying volumes and sequences of reagents, transforming a static single-function device into a dynamic multi-functional system
3Extent of automation
If cartridge-based pneumatic delivery systems are used, then reagent delivery can be automated, but dead volume in the microchannels reduces efficiency
Solution Approach 1:
The patent segments the microchannel system into distinct zones with the valve positioned to create a clear separation between the reagent reservoir and the delivery channel. This segmentation eliminates dead volume by ensuring reagents flow directly from the reservoir through the valve into the channel without stagnant zones, while maintaining automated pneumatic delivery
4Ease of operation
If membrane-based valving is used, then fluid flow can be controlled, but the membrane requires continuous actuation to remain closed
Solution Approach 1:
The patent inverts the conventional membrane valve operation by using a normally open configuration where the membrane remains open by default and closes only when pneumatic pressure is applied. This eliminates the need for continuous actuation to maintain the closed state, reducing energy consumption and simplifying operation while maintaining ease of flow control
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
The device ensures reliable, versatile, and compact operation with reduced risk of cross-contamination and dead volumes, enabling efficient mixing and reagent delivery for various applications, including biological tissue sampling.
Implementation Method 1
Each valve comprises a deflectable member displaceable between a valve closed position in which fluid communication between the inlet channel and common outlet channel is closed, and a valve open position in which fluid communication between the inlet channel and common outlet channel is open
Implementation Method 2
utilizing pneumatic or hydraulic actuation to control fluid flow
Implementation Method 3
utilizing pneumatic or hydraulic actuation to control fluid flow
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
Microfluidic network device (2) configured to supply reagents to a biological tissue sampling device (1), comprising a plurality of microfluidic inlet channels (12) connected to respective sources of said reagents, at least one common outlet channel (22), and a plurality of valves (36) interconnecting an outlet end (14) of each of said plurality of inlet channels to said at least one common outlet channel.