MEMS Vibration Element Thickness Tuning for Frequency Adaptation
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Solution Overview
Problem
Conventional vibration-driven energy harvesters require significant redesign and effort to adapt to varying predominant frequencies in different environments, making them costly and inefficient for multiple frequency applications.
Innovation Solution
A MEMS vibration element manufacturing method involving etching a base material to form fixed and movable electrodes with different thicknesses, where the elastic supporting unit has a thickness smaller than both, allowing for adjustable resonance frequency without re-creating masks, enabling easier adaptation to various environmental vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the thickness, length, and other dimensions of the elastic supporting unit are re-designed to match a target environment's predominant frequency, then the resonance frequency can be matched with the predominant frequency, but the device complexity and manufacturing cost increase significantly
Solution Approach 1:
The patent separates the elastic supporting unit from the electrode structures by using selective etching. The elastic supporting unit is etched to a different depth than the electrodes, creating distinct thicknesses. This segmentation allows independent optimization of the elastic supporting unit's dimensions for resonance frequency matching without redesigning the entire device
Solution Approach 2:
The patent changes the thickness parameter of the elastic supporting unit relative to the electrodes. By etching the elastic supporting unit to a second thickness that is less than the first thickness of the electrodes, the resonance frequency can be adjusted to match predominant environmental frequencies without redesigning other components
2Adaptability or versatility
If conventional vibration-driven energy harvesters are adapted to various predominant frequencies by re-designing the elastic supporting unit, then they can work in different environments, but a lot of cost and effort are required
Solution Approach 1:
The patent creates a universal manufacturing process where the same base material structure serves multiple functions: the electrodes maintain their full thickness for electrical function, while the elastic supporting unit is selectively thinned to adjust resonance frequency. This allows a single device design to be adapted to different environments by simply modifying the elastic supporting unit's thickness through etching parameters
Solution Approach 2:
The patent enables easy adaptation to various predominant frequencies by changing only the etching depth parameter for the elastic supporting unit. The second thickness is controlled to be less than the first thickness of the electrodes, allowing frequency tuning without redesigning the entire device or creating new masks
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
Enables the easy manufacturing of MEMS vibration elements adaptable to different environmental vibrations, reducing costs and effort by allowing precise adjustment of the elastic supporting unit's thickness to match resonance frequencies, thereby enhancing power generation efficiency.
Implementation Method 1
an elastic supporting unit that elastically supports the movable electrode with respect to the fixed electrode
Data Source
AI summary
A method of manufacturing a MEMS vibration element having a fixed electrode, a movable electrode, and an elastic supporting unit that elastically supports the movable electrode with respect to the fixed electrode includes: etching a base material having a first thickness to form the fixed electrode and the movable electrode; and etching the base material to form the elastic supporting unit having a second thickness, the second thickness being less than the first thickness.