Piezoelectric Microfluidic Pump Structure for Quiet Gas Transfer
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Solution Overview
Problem
Conventional miniature pneumatic devices are bulky, noisy, and not portable due to their size and noise generation during operation, making them unsuitable for portable medical or other equipment where miniaturization and silence are required.
Innovation Solution
A miniature fluid control device utilizing a piezoelectric actuator with a suspension plate, outer frame, and piezoelectric ceramic plate that generates a pressure gradient for high-speed gas flow, allowing for compact, silent, and portable operation by facilitating gas transfer through a housing with a gas collecting plate and base, and a miniature valve device for one-way gas flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional motors or pressure valves are used in pneumatic devices, then gas transfer function is achieved, but device volume becomes large and portability is reduced
Solution Approach 1:
The patent replaces conventional motors and pressure valves with a piezoelectric actuator that utilizes piezoelectric effect to generate mechanical vibrations. This substitution eliminates bulky mechanical components while maintaining gas transfer capability through acoustic radiation pressure and cavitation effects in the fluid medium.
Solution Approach 2:
The patent changes the operating parameters by using high-frequency electrical signals (typically 20-100 kHz) to drive the piezoelectric actuator, creating ultrasonic vibrations in the fluid. This parameter change enables compact device design while achieving effective gas transfer through acoustic cavitation and microstreaming.
2Object-generated harmful factors
If conventional motors or pressure valves are used, then gas transfer is achieved, but noise is generated during operation
Solution Approach 1:
The patent replaces noisy mechanical motors and pressure valves with a piezoelectric-based acoustic field system. The gas transfer is achieved through ultrasonic cavitation and acoustic radiation pressure rather than mechanical motion, thereby eliminating the characteristic noise of conventional pneumatic components.
Solution Approach 2:
The patent utilizes phase transitions of gas bubbles in the fluid medium through acoustic cavitation. The ultrasonic vibrations cause bubbles to oscillate and collapse, generating localized high pressure and microjets that drive fluid and gas transport without mechanical contact, thus reducing noise.
3Productivity
If device size is reduced for portability, then compactness is achieved, but gas transfer efficiency may be compromised
Solution Approach 1:
The patent employs mechanical vibration at ultrasonic frequencies generated by the piezoelectric actuator to enhance gas transfer efficiency. The high-frequency vibrations create cavitation bubbles and microstreaming in the fluid, which dramatically improve mass transfer rates and gas transport efficiency despite the compact device volume.
Solution Approach 2:
The patent exploits phase transitions of gas-liquid interfaces through acoustic cavitation. The ultrasonic field causes repeated formation, growth, and collapse of bubbles, creating intense local mixing and transport effects that maintain high gas transfer efficiency in a compact configuration.
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 solution enables efficient, quiet, and portable gas transfer with a compact design, suitable for medical or other portable equipment, achieving high-speed gas flow and silent operation while maintaining a small volume and thickness.
Implementation Method 1
When a piezoelectric ceramic plate is operated at a high frequency, a pressure gradient is generated in the fluid channels of a miniature fluid control device to facilitate the gas to flow at a high speed
Implementation Method 2
When a piezoelectric ceramic plate is operated at a high frequency, a pressure gradient is generated in the fluid channels of a miniature fluid control device to facilitate the gas to flow at a high speed
Implementation Method 3
When a voltage is applied to the piezoelectric ceramic plate, the suspension plate is driven to undergo the curvy vibration
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A miniature fluid control device (1A) includes a piezoelectric actuator (13) and a housing (1a). The piezoelectric actuator (13) comprises a suspension plate (130), an outer frame (131), at least one bracket (132) and a piezoelectric ceramic plate (133). The piezoelectric ceramic plate (133) is attached on a first surface (130b) of the suspension plate (130) and has a length not larger than that of the suspension plate (130). The housing (1a) includes a gas collecting plate (16) and a base (10). The gas collecting plate (16) is a frame body with a sidewall (168) and comprises a plurality of perforations (163, 164). The base (10) seals a bottom of the piezoelectric actuator (13) and has a central aperture (120) corresponding to the middle portion (130d) of the suspension plate (130). When the voltage is applied to the piezoelectric actuator (13), the suspension plate (130) is permitted to undergo the curvy vibration, the fluid is transferred from the central aperture (120) of the base (10) to the gas-collecting chamber (162), and exited from the perforations (163, 164).