Electrostatic Disc Pump for High-Frequency Fluid Actuation
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Solution Overview
Problem
Disc pumps operating at high frequencies for portable electronic devices face challenges in maintaining efficiency due to the need for high-frequency valves that can handle high amplitude pressure oscillations within disc-shaped cavities, where conventional valves and actuator technologies like piezo-electric mechanisms are limited in flexibility and compatibility with varying fluid conditions.
Innovation Solution
An electrostatically-driven disc pump system with a flexible actuator and a valve mechanism that utilizes a flap valve design, capable of operating at high frequencies, is developed. The system includes a conductive plate and actuator with a constant or variable surface charge, driven by an electrostatic field to generate pressure oscillations, and a valve that responds rapidly to differential pressures to control fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional valves are used in disc pumps operating at high frequencies, then the valve structure is simple and easy to manufacture, but the valves cannot respond rapidly enough to high frequency pressure oscillations and cannot handle high amplitude pressure variations
Solution Approach 1:
The patent replaces conventional mechanical valve actuation with electrostatic actuation. The electrostatically-driven actuator uses electric fields to directly drive the valve flap, eliminating complex mechanical linkages and enabling rapid response to high frequency pressure oscillations. This substitution of mechanical systems with electrostatic fields resolves the contradiction between response speed and mechanical complexity.
2Adaptability or versatility
If piezo-electric actuators are used to drive the end wall, then the actuator provides precise control, but the actuator lacks flexibility and compatibility with varying fluid conditions
Solution Approach 1:
The electrostatic actuator allows for dynamic adjustment of operating parameters such as voltage amplitude and frequency, enabling adaptation to varying fluid conditions while maintaining reliable performance. The electrostatic field can be easily modulated to match different pressure oscillation requirements, providing both flexibility and consistency in actuator performance across diverse operating conditions.
3Productivity
If the disc pump operates at high frequencies for portable devices, then the pump size is reduced and operation is inaudible, but conventional valves cannot operate at these high frequencies
Solution Approach 1:
The electrostatically-driven valve mechanism replaces conventional mechanical valves, enabling operation at high frequencies (20 kHz and higher) required for portable device applications. The electrostatic actuation provides the rapid response time necessary for high-frequency operation while maintaining reliable valve function, allowing the pump to achieve reduced size and inaudible operation without sacrificing valve reliability.
4Productivity
If high amplitude pressure oscillations are generated in the cavity, then the pumping effect is significantly increased, but the valves must be capable of handling these high amplitude oscillations
Solution Approach 1:
The electrostatically-driven valve mechanism is designed to handle high amplitude pressure oscillations through direct electrostatic actuation of the valve flap. This eliminates the need for complex mechanical components that would be required to withstand and respond to high amplitude pressure variations, thereby maintaining pumping efficiency while avoiding increased mechanical complexity.
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 electrostatically-driven disc pump system enhances flexibility and efficiency by allowing operation at high frequencies without the constraints of piezo-electric actuators, achieving effective fluid pumping with minimal energy dissipation and maintaining high amplitude pressure oscillations, suitable for portable devices requiring inaudible operation.
Implementation Method 1
The actuator is driven by an electrostatic field to generate pressure oscillations
Implementation Method 2
Acoustic resonance to achieve fluid pumping from defined inlets and outlets
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
A disc pump includes a pump body having a cavity for containing a fluid. The disc pump also includes an actuator adapted to hold an electrostatic charge to cause an oscillatory motion at a drive frequency. The disc pump further includes a conductive plate positioned to face the actuator outside of the cavity and adapted to provide an electric field of reversible polarity, the conductive plate being electrically associated with the actuator to cause the actuator to oscillate at the drive frequency in response to reversing the polarity of the electric field. The disc pump further includes a valve disposed in at least one of a first aperture and a second aperture in the pump body. The oscillation of the actuator at the drive frequency causes fluid flow through the first aperture and the second aperture when in use.