Shallow-Chamber Microfluidic Actuator for Higher MEMS Flow Rate
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Solution Overview
Problem
Conventional micro fluid actuators manufactured by MEMS processes have insufficient flow rates due to small displacement of the piezoelectric layer, limiting their miniaturization and efficiency in fluid transportation applications.
Innovation Solution
A micro fluid actuator is designed using a semiconductor thin film process with a shallow storage chamber and a layered structure comprising a substrate, chamber layer, vibration layer, electrode layers, and a flow channel layer, where driving power with different phases is applied to the electrode layers to drive the vibration layer reciprocally, enhancing fluid compression and flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the conventional micro fluid actuator is miniaturized by MEMS process, then the structure size is reduced, but the flow rate transmitted becomes insufficient due to small piezoelectric layer displacement
Solution Approach 1:
The patent changes the depth parameter of the storage chamber from conventional deep structure to shallow structure (depth of 1-10 micrometers). This parameter change increases the fluid compression ratio when the piezoelectric layer actuates, thereby improving flow rate despite the miniaturized structure. The shallow chamber design allows even small piezoelectric displacements to generate sufficient fluid pressure for effective pumping.
Solution Approach 2:
The patent transitions from a deep vertical chamber structure to a shallow horizontal chamber structure. By changing the dimensional orientation of the storage chamber, the design maximizes the compression effect in the horizontal plane while maintaining miniaturization. This dimensional change allows the small piezoelectric displacement to be more effectively translated into fluid flow.
2Productivity
If the piezoelectric layer displacement is increased to improve flow rate, then the flow rate transmitted increases, but the structure complexity and manufacturing difficulty increase
Solution Approach 1:
Rather than increasing piezoelectric layer displacement through complex multi-layer piezoelectric structures or larger actuator sizes, the patent simply changes the chamber depth parameter to shallow. This single parameter change achieves high flow rates with conventional piezoelectric layers, avoiding increased device complexity while maintaining manufacturing simplicity through standard MEMS processes.
3Quantity of substance
If the storage chamber depth is increased to accommodate more fluid, then the fluid volume increases, but the fluid compression ratio decreases and flow efficiency is reduced
Solution Approach 1:
The patent optimizes the chamber depth parameter to a shallow range (1-10 micrometers) that achieves the right balance between fluid volume and compression ratio. The shallow depth ensures high compression ratios for efficient pumping while the lateral dimensions are sufficient to accommodate the required fluid volume. This parameter optimization resolves the contradiction between volume and efficiency.
Solution Approach 2:
The patent compensates for reduced vertical depth by expanding the chamber in horizontal dimensions. The storage chamber is designed with larger lateral area to maintain sufficient fluid volume while keeping the depth shallow. This dimensional redistribution allows the chamber to hold adequate fluid while maintaining high compression ratios for efficient actuation.
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 increases the fluid compression ratio and flow efficiency, overcoming the limitations of small piezoelectric displacement, enabling effective fluid transportation in extremely miniaturized structures, which is beneficial for various industrial and biomedical applications.
Implementation Method 1
a piezoelectric actuation layer (1e)... Driving power which have different phases are provided to the upper electrode layer and the lower electrode layer, so as to drive and control the vibration layer (1c) to displace in a reciprocating manner
Data Source
AI summary
A micro fluid actuator includes an orifice layer, a flow channel layer, a substrate, a chamber layer, a vibration layer, a lower electrode layer, a piezoelectric actuation layer and an upper electrode layer, which are stacked sequentially. An outflow aperture, a plurality of first inflow apertures and a second inflow aperture are formed in the substrate by an etching process. A storage chamber is formed in the chamber layer by the etching process. An outflow opening and an inflow opening are formed in the orifice layer by the etching process. An outflow channel, an inflow channel and a plurality of columnar structures are formed in the flow channel layer by a lithography process. By providing driving power which have different phases to the upper electrode layer and the lower electrode layer, the vibration layer is driven to displace in a reciprocating manner, so as to achieve fluid transportation.