Miniature Fluid Control Device Piezoelectric Actuator Vibration Damping

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Solution Overview

Problem

Conventional miniature fluid control devices are bulky, noisy, and inefficient due to insufficient adhesive thickness and rigidity, leading to energy loss and noise generation during operation.

Innovation Solution

A miniature fluid control device with a piezoelectric actuator featuring a square suspension plate and a reduced thickness outer frame, where the adhesive layer is increased in thickness to enhance adhesion and absorb vibration energy, and the components are etched at the same depth for a coplanar surface, improving kinetic energy utilization and noise reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the adhesive layer thickness is increased to improve vibration energy absorption and reduce noise, then the device structure becomes more complex and manufacturing difficulty increases

Engineering Contradiction:
ImprovenoiseVSAvoiddevice structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines the adhesive layer with the gap between the resonance plate and outer frame into a single functional element. The adhesive layer is applied to fill the gap h0, creating a unified structure that serves both bonding and vibration damping functions, eliminating the need for separate damping components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a thin film adhesive layer (thickness t1) that is flexible enough to absorb vibration energy but thin enough to maintain structural integrity. The adhesive layer acts as a flexible damping element that reduces noise while maintaining the compact device structure

Inventive Principle:
Principle #30Flexible shells and thin films

2Length of moving object

If the outer frame thickness is reduced to achieve a slimmer device profile, then the structural rigidity decreases and manufacturing precision becomes more difficult to maintain

Engineering Contradiction:
Improvedevice profile thicknessVSAvoidetching depth consistency
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent changes the etching depth parameter from multiple depth levels to a single uniform depth (h1) for all components. This parameter simplification allows for consistent etching of the suspension plate, outer frame, and bracket at the same depth, ensuring coplanar surfaces and improving manufacturing precision while enabling a thinner overall profile

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating a coplanar surface specifically at the interface between the suspension plate, outer frame, and bracket through uniform etching. This localized precision at the critical interface area maintains structural integrity while allowing reduced overall thickness

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If multiple etching depths are used to create height differences for adhesive application, then the manufacturing process becomes more complex with multiple etching steps

Engineering Contradiction:
Improveadhesive applicationVSAvoidetching process
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

Instead of creating height differences through multiple etching depths to facilitate adhesive application, the patent inverts the approach by using a single etching depth and allowing the adhesive to fill the gap naturally. The adhesive layer thickness is controlled by the gap dimension rather than by creating stepped surfaces, simplifying the etching process to a single step

Inventive Principle:
Principle #13The other way round (Inversion)

4Volume of moving object

If the device is miniaturized to meet portable application requirements, then the volume of motors and pressure valves must be reduced, but this leads to increased noise and reduced functionality

Engineering Contradiction:
Improvedevice volumeVSAvoidnoise
Core Design Contradiction:
Volume of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent replaces traditional mechanical pneumatic components (motors and pressure valves) with a piezoelectric actuator that directly drives the suspension plate to generate acoustic waves. This mechanical substitution eliminates the need for bulky motors and pressure valves, achieving miniaturization while reducing noise through the piezoelectric effect

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses mechanical vibration of the suspension plate at resonant frequency to generate acoustic waves for fluid transport. By operating at resonance, the device achieves efficient fluid pumping with minimal energy input and reduced noise, enabling compact design suitable for portable applications

Inventive Principle:
Principle #18Mechanical vibration

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 device achieves a slim, silent, and power-saving design, suitable for portable and wearable applications, with improved flowrate and pressure maintenance, and reduced noise and defectiveness.

Implementation Method 1

the piezoelectric actuator 12 is actuated by an applied voltage, the suspension plate 121 of the piezoelectric actuator 12 is vibrated along a vertical direction in a reciprocating manner

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the thickness of the adhesive layer 13 can be increased... The increase of the thickness of the adhesive layer 13 can assist in absorbing vibration energy and reduce noise

Methodology Applied
Scientific EffectVibration energy absorption: Damping

Implementation Method 3

a compressible chamber 10 is defined between the resonance plate 142 and the piezoelectric actuator 12... As the volume of the compressible chamber 10 shrinks, the fluid exits through the first perforation 111

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3290699B1Miniature fluid control device
Publication Date: 2020.10.28 MICROJET TECH
  • EP3290699B1 patent drawingFigure 1A
  • EP3290699B1 patent drawingFigure 1B
  • EP3290699B1 patent drawingFigure 2A

AI summary

A miniature fluid control device (1) includes a piezoelectric actuator (13), a gas collecting plate (16) and a base (10). The piezoelectric actuator (13) includes a suspension plate (130), an outer frame (131), at least one bracket (132) and a piezoelectric ceramic plate (133). The suspension plate (130) is a square plate. The outer frame (131) is arranged around the suspension plate (130). A surface of the outer frame (131) and a surface of the suspension plate (130) are coplanar with each other. The gas collecting plate (16) is a frame body with an accommodation space (16a). The base (10) includes a gas inlet plate (11) and a resonance plate (12). The base (10) is disposed within the accommodation space (16a) to seal the piezoelectric actuator (13). An adhesive layer (136) is arranged between the second surface (131a) of the outer frame (131) of the piezoelectric actuator (13) and the resonance plate (12). Consequently, a depth of a compressible chamber (121) between the piezoelectric actuator (13) and the resonance plate (12) is maintained.