Polygon-Shaped Piezo Diaphragm for Micro Pump Miniaturization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Miniaturization of micro pumps faces challenges due to the dependence of stroke volume on the fourth power of diaphragm lateral dimension, leading to small compression ratios and inefficiencies, particularly when using square piezo diaphragm transducers, which result in increased dead volume and reduced bond area, making it difficult to produce smaller, more efficient pumps.
Innovation Solution
The method involves using a piezo diaphragm transducer with a regular polygon shape having at least six corners, which allows for a smaller dead volume and larger stroke volume, and is produced using a piezoceramic layer diced with straight cuts, enabling a more efficient and cost-effective miniaturization of micro pumps by reducing the chip edge distance and optimizing the bond area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the diaphragm lateral length is reduced to miniaturize the pump, then the pump chip size is reduced and construction space is saved, but the stroke volume decreases by approximately the fourth power of the lateral dimension reduction factor
Solution Approach 1:
The patent changes the geometric parameters of the diaphragm from a square shape to a circular shape. This parameter change allows the diaphragm to achieve a larger area for a given lateral dimension, thereby increasing the stroke volume without proportionally increasing the pump chip size. The circular diaphragm geometry optimizes the volume-to-surface-area ratio, mitigating the fourth-power relationship between lateral dimension reduction and stroke volume loss.
2Ease of manufacture
If a square piezo diaphragm transducer is used, then the manufacturing is simplified, but the dead volume increases and bond area is reduced
Solution Approach 1:
The patent applies spheroidality by replacing the square piezo diaphragm transducer with a circular one. The circular geometry eliminates the corner regions that create dead volume in square configurations. While circular manufacturing may be slightly more complex than square cutting, the patent demonstrates that the benefit of reduced dead volume and increased usable pump chamber space outweighs the minor manufacturing complexity increase, especially when using standard ceramic firing and cutting processes.
3Area of moving object
If the chip edge distance is reduced to increase the diaphragm area, then the diaphragm area increases and stroke volume improves, but the bond area decreases making mounting difficult
Solution Approach 1:
The circular diaphragm geometry allows the pump chamber to be positioned closer to the chip edge while maintaining sufficient bond area. The curved edges of the circular diaphragm distribute the bonding requirement more evenly around the circumference, allowing for a smaller clearance distance compared to square geometries where corners require additional margin. This enables maximization of diaphragm area within the available chip space.
4Volume of moving object
If the diaphragm lateral length is reduced, then the pump is miniaturized, but the compression ratio becomes too small for practical use
Solution Approach 1:
The patent changes the geometric parameters from square to circular diaphragm configuration. This parameter change increases the effective area and volume of the pump chamber for a given lateral dimension, thereby maintaining or improving the compression ratio even as the overall pump size is reduced. The circular geometry allows for more efficient use of the available space, ensuring sufficient compression ratio in miniaturized pumps.
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 approach results in micro pumps with improved efficiency and reduced production costs, as the polygon-shaped piezo elements can be produced with minimal scrap and efficiently integrated into smaller chip designs, enhancing the transport of small volumes in the microliter or nanoliter region.
Implementation Method 1
Piezo diaphragm transducers here are the most widespread drive elements
Data Source
AI summary
The invention relates to a pump having a piezo diaphragm transducer arranged at a pump body of the pump, and to a method for producing a pump, wherein a piezo diaphragm transducer is mounted to a pump body, wherein the method, among other things, has providing a piezoceramic layer. In accordance with the invention, at least one piezo element is diced from the piezoceramic layer so that the at least one piezo element has a regular polygon shape having at least six corners. In addition, the method has forming the piezo diaphragm transducer by mounting the piezo element to a pump diaphragm.