Bidirectional Micro Pump Using Segmented Piezo Membrane
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Solution Overview
Problem
Conventional micro pumps face challenges in increasing flow rate due to their small size, as they typically allow fluid flow only when the vibrating membrane is displaced in one direction.
Innovation Solution
A micro pump design featuring a vibrating membrane with a piezoelectric element, where the membrane displaces vertically to alternately flow fluid between an upper and a lower space, allowing fluid to flow out and in from both spaces during upward and downward displacements, with strategically positioned and shaped inflow and outflow paths to prevent backflow without check valves, enhancing durability and flow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the micro pump is made small in size, then the device compactness is improved, but the flow rate decreases
Solution Approach 1:
The pump body is divided into an upper space and a lower space separated by the vibrating membrane. Each space has independent inflow and outflow paths, allowing simultaneous fluid processing in both spaces. This segmentation enables the small device to achieve doubled flow rate by processing fluid in parallel through both spaces during each vibration cycle.
2Device complexity
If the vibrating membrane is displaced in one direction only, then the device complexity is reduced, but the flow rate is limited
Solution Approach 1:
The piezoelectric element generates periodic vibrations that cause the vibrating membrane to alternately displace upward and downward. During upward displacement, fluid flows from the upper space out and into the lower space. During downward displacement, fluid flows from the lower space out and into the upper space. This periodic bidirectional action doubles the flow rate compared to unidirectional displacement while maintaining simple path configurations.
3Volume of moving object
If inflow and outflow paths are positioned closely, then the device size is reduced, but backflow occurs reducing efficiency
Solution Approach 1:
The inflow paths and outflow paths are designed with asymmetric positioning and shaping. The outflow paths are positioned to utilize inertial forces generated during membrane vibration, creating a flow direction preference that prevents backflow into the inflow paths. This asymmetric design maintains compact device size while ensuring unidirectional flow efficiency.
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 doubles the flow rate compared to conventional micro pumps by allowing fluid flow in both directions of membrane displacement, while improving durability by preventing inflow and outflow port overlap and utilizing inertial forces for enhanced outflow efficiency.
Implementation Method 1
a vibrating membrane on which a piezoelectric element is stacked
Data Source
AI summary
A micro pump includes: a vibrating membrane on which a piezoelectric element is stacked; an upper space provided in contact with an upper surface of the vibrating membrane; and a lower space provided in contact with a lower surface of the vibrating membrane, wherein by displacing the vibrating membrane toward the upper space, a fluid flows out from the upper space to an outside and flows in from the outside to the lower space, and wherein by displacing the vibrating membrane toward the lower space, the fluid flows out from the lower space to the outside and flows in from the outside to the upper space.