Rotary Valve System for Microfluidic Liquid Delivery
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Solution Overview
Problem
Conventional syringe pump systems for microfluidic liquid delivery face issues such as liquid waste and air trapping due to residual volumes in the pump and valve, which complicates liquid changes and air evacuation, and are not well-suited for accurate and efficient microfluidic pumping with selectable input and output channels.
Innovation Solution
A rotary valve system with a stator and rotor design that includes distinct rotor input and output fluid channels, a position sensing system using magnetic field sensors, and a compact, robust pump configuration, allowing for precise angular positioning and minimal dead volume to reduce waste and facilitate air evacuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional syringe pump systems are used for microfluidic liquid delivery, then liquid delivery can be achieved, but liquid waste and air trapping occur due to residual volumes in the pump and valve
Solution Approach 1:
The valve is divided into distinct stator and rotor components with separate fluid channels. The rotor contains dedicated input and output channels that are spatially segmented and only connect to stator channels at specific angular positions, eliminating residual volume accumulation zones and enabling complete liquid evacuation.
Solution Approach 2:
The harmful residual volume is extracted from the system by designing the rotor channels to connect to stator channels only at specific angular positions. This extraction of connectivity eliminates the dead volume zones where liquid would otherwise remain trapped, allowing complete liquid transfer without waste.
2Reliability
If conventional syringe pump systems are used, then liquid delivery is possible, but air evacuation becomes difficult due to dead volume zones within the pump and valve
Solution Approach 1:
The valve architecture segments the fluid path into distinct rotor input channels and rotor output channels that connect to stator channels at separate angular positions. This segmentation eliminates dead volume zones where air would be trapped, enabling reliable air evacuation through the complete fluid path.
Solution Approach 2:
Dead volume zones are extracted from the system by designing channels that maintain open flow paths without enclosed spaces. The rotor channels connect to stator channels only at specific angular positions, preventing air entrapment and enabling complete air evacuation from the system.
3Productivity
If conventional syringe pump systems are used, then liquid delivery can be achieved, but liquid changes require washing through residual volume which increases time and waste
Solution Approach 1:
The valve channels are segmented into distinct input and output paths with no overlapping residual zones. When changing liquids, the rotor can be positioned to create a direct flush path from any stator input channel through the rotor channel to any stator output channel, enabling rapid washing without navigating complex residual volume zones.
Solution Approach 2:
Residual volume is extracted from the system architecture, eliminating the need for extensive washing procedures. The channel design ensures complete liquid transfer and easy flushing by maintaining open paths without enclosed dead zones where liquid would be trapped during transitions.
4Loss of substance
If a rotary valve with distinct rotor input and output channels is used, then minimal dead volume and waste are achieved, but valve manufacturing complexity increases
Solution Approach 1:
The valve is manufactured as segmented stator and rotor components that can be produced using standard machining or molding processes. The segmentation into separate input and output channels in the rotor, combined with the stator's corresponding channels, achieves minimal dead volume while maintaining manufacturability through modular component design.
5Measurement precision
If a position sensing system with magnetic field sensors is used, then precise angular positioning is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The mechanical position sensing system is replaced with a magnetic field-based sensing system. Magnetic markers embedded in the rotor are detected by magnetic field sensors in the stator, providing precise angular position measurement without mechanical contact or complex mechanical linkages, thereby reducing overall mechanical complexity while maintaining high precision.
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 rotary valve system enables accurate and efficient delivery of liquids with minimal waste, effective air evacuation, and precise control, making it suitable for microfluidic applications and automated flow cytometry with reduced manufacturing and operational costs.
Implementation Method 1
a position sensing system using magnetic field sensors
Data Source
Figure 1a~1b
Figure 2a~3c
Figure 4a~5a
AI summary
Pump system with rotary valve (2) comprising a pump (6) and a valve (8), the valve including a stator (18) comprising a stator body (32) and a plurality of stator fluid channels (34) connected to fluid ports (56) coupled to respective fluid supply and delivery lines, and a rotor (20) comprising a rotor body (36) and at least one rotor fluid channel (38). The stator body comprises a valve bearing surface (50) and the rotor body (36) comprises a complementary valve bearing surface slidably engaging the stator valve bearing surface, the rotor fluid channels (38) configured to be brought into fluid communication with stator fluid channels (34) as a function of the relative angular position of the rotor with respect of the stator about a rotor axis A.