Conical Membrane Micro Pump Valve for Precise Pulsatile Dosing
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Solution Overview
Problem
Current micro-pumps for insulin delivery face challenges in achieving precise flow rate accuracy, avoiding air bubbles, and maintaining efficient operation with particulate materials, while also requiring cost-effective manufacturing and assembly processes to support periodic use.
Innovation Solution
A pulsatile micro-pump design featuring a conical shaped valve seat and a membrane with a hole, allowing fluid flow when pressure differences exceed a certain threshold, combined with elastomeric materials for effective sealing and reduced membrane flexing, which enhances flow rate and prevents reverse fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a membrane valve is used to control fluid flow in the micro-pump, then flow direction control is improved, but membrane flexing increases causing volume variation and reduced delivery precision
Solution Approach 1:
The patent applies curvature by designing the membrane with a pre-formed dome shape and the valve seat with a corresponding curved surface. This curvature distribution allows the membrane to flex uniformly during operation, reducing stress concentration and minimizing volume variation caused by excessive flexing, thereby maintaining delivery precision while enabling reliable flow direction control.
Solution Approach 2:
The patent changes physical parameters of the membrane including its thickness, material composition, and pre-tensioning forces. By optimizing these parameters, the membrane achieves the right balance between flexibility (for flow control) and stiffness (for maintaining volume precision), resolving the contradiction between reliable flow direction control and manufacturing precision.
2Reliability
If the membrane is made more flexible to improve sealing, then sealing effectiveness is improved, but volume variation increases reducing flow rate accuracy
Solution Approach 1:
The patent optimizes membrane parameters including thickness, material properties, and pre-tensioning to achieve the optimal balance between flexibility and stiffness. The membrane is made sufficiently flexible to ensure effective sealing against the valve seat, while maintaining adequate stiffness through controlled thickness and pre-tensioning to minimize volume variation and maintain flow rate accuracy within +/- 2.50 nl.
Solution Approach 2:
The curved dome shape of the membrane distributes flexing stresses more evenly during operation, allowing the membrane to be sufficiently flexible for sealing while reducing the impact of flexing on volume variation. This geometric optimization enables both good sealing and acceptable flow rate accuracy.
3Manufacturing precision
If the pumping chamber volume is reduced to improve dosing precision, then dosing accuracy is improved, but the chamber becomes more susceptible to air bubble retention
Solution Approach 1:
The patent designs the pumping chamber with curved surfaces and optimized geometry that facilitate air bubble removal. The chamber shape includes features that promote bubble coalescence and directed flow paths that guide bubbles toward the inlet, ensuring that even in a small volume chamber (50-500 nl), air bubbles are effectively managed without compromising dosing accuracy.
4Weight of moving object
If conventional micro-pump designs are used, then portability is achieved, but flow rate accuracy varies by more than +/- 2.50 nl
Solution Approach 1:
The patent employs curved membrane design and optimized chamber geometry to minimize dead volumes and improve fluid displacement efficiency. This enables miniaturized portable pumps to achieve flow rate accuracy within +/- 2.50 nl by reducing the impact of manufacturing tolerances and minimizing air entrapment, while maintaining the portability advantage of small size.
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 design achieves precise fluid delivery with reduced volume variation, effective sealing in the presence of particles, and cost-effective manufacturing, suitable for high-volume production and low-cost applications.
Implementation Method 1
When the pressure on the side of the membrane from which liquid is allowed to enter and pass through the micro valve, exceeds the pressure on the opposite side of the membrane, the membrane releases its seal on the valve seat and fluid leaks from one side of the membrane to the opposite side
Implementation Method 2
Passive, normally closed one way membrane micro valve designs are commonly employed in micro pump design... The construction of these micro valves typically comprises a membrane that serves to separate the fluid at the inlet to the pumping chamber from that present in the pumping chamber
Data Source
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AI summary
An one way valve comprising: a conical shaped valve seat (1); and a membrane (2) having a hole (3) that is located around the conical valve seat, such that a surface (60) of the valve seat seals (1) onto an inner periphery (61) of the hole (3) in the membrane (2), wherein, in use, the membrane (2) is deflected from the surface (60) of the valve seat (1) to provide a fluid path across the membrane (2) and allowing fluid to flow from one side of the membrane (2) to the other.