MEMS Vibrating Membrane Amplitude Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitance-type MEMS elements face challenges in achieving high sensitivity while maintaining an improved Acoustic Overload Point (AOP), as the vibrating membrane's central and peripheral portions exhibit significant amplitude differences, leading to reduced effective displacement area and compromised AOP.
Innovation Solution
The MEMS element incorporates a vibrating membrane with a central pillar connecting it to the backplate and multiple vibrating portions formed by pillar side slits and peripheral portion side slits, which helps to distribute amplitude evenly across the membrane, reducing amplitude differences between the central and peripheral portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the spring constant of the vibrating membrane is reduced to increase sensitivity, then sensitivity is improved, but the amplitude difference between central and peripheral portions increases causing the vibrating membrane and backplate to contact each other, deteriorating the AOP
Solution Approach 1:
The vibrating membrane is divided into multiple vibrating portions by forming slits (first slits extending from the central portion toward the peripheral portion, and second slits extending from the peripheral portion toward the central portion). This segmentation creates independent vibration regions that reduce the overall amplitude while maintaining sensitivity, preventing contact between the vibrating membrane and backplate.
Solution Approach 2:
Different regions of the vibrating membrane are given different characteristics through the slit configuration. The central portion and peripheral portion are connected to the backplate via pillars, while the regions between them form vibrating portions with controlled amplitude. This local differentiation allows the central and peripheral portions to have smaller amplitude differences, improving AOP while maintaining sensitivity.
2Power
If the amplitude at the central portion is increased to improve detection signal, then detection signal increases, but the amplitude difference between central and peripheral portions increases, reducing the effective displacement area
Solution Approach 1:
The vibrating membrane is divided into multiple vibrating portions by forming slits (first slits extending from the central portion toward the peripheral portion, and second slits extending from the peripheral portion toward the central portion). This segmentation creates independent vibration regions that reduce the overall amplitude while maintaining sensitivity, preventing contact between the vibrating membrane and backplate.
Solution Approach 2:
Different regions of the vibrating membrane are given different characteristics through the slit configuration. The central portion and peripheral portion are connected to the backplate via pillars, while the regions between them form vibrating portions with controlled amplitude. This local differentiation allows the central and peripheral portions to have smaller amplitude differences, improving AOP while maintaining sensitivity.
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
This configuration enhances the AOP by ensuring a larger detection signal while maintaining sensitivity, as the evenly distributed amplitude across the vibrating membrane reduces distortion and improves signal output.
Implementation Method 1
a capacitance-type MEMS element detects, as a capacitance change between the movable electrode and the fixed electrode, displacement of the movable electrode caused by a vibration of the vibrating membrane
Data Source
AI summary
A MEMS element in which a backplate including a fixed electrode and a vibrating membrane including a movable electrode are disposed on a substrate including a back chamber, so as to face each other via a spacer, the vibrating membrane includes a pillar connected to the backplate, pillar side slits, and peripheral portion side slits, and a plurality of vibrating portion is formed in the vibrating membrane. The central portion of the vibrating membrane is connected to the backplate by the pillar, so that the amplitude of the central portion can be suppressed. In each of a plurality of vibrating portions, the pillar side slits are disposed on a portion side in which the pillar and the vibrating membrane are joined and the peripheral portion side slits are disposed at the peripheral portion, thereby decreasing the difference in the amplitude amount between the central portion and the peripheral portion.A MEMS element in which a backplate including a fixed electrode and a vibrating membrane including a movable electrode are disposed on a substrate including a back chamber, so as to face each other via a spacer, the vibrating membrane includes a pillar connected to the backplate, pillar side slits, and peripheral portion side slits, and a plurality of vibrating portion is formed in the vibrating membrane. The central portion of the vibrating membrane is connected to the backplate by the pillar, so that the amplitude of the central portion can be suppressed. In each of a plurality of vibrating portions, the pillar side slits are disposed on a portion side in which the pillar and the vibrating membrane are joined and the peripheral portion side slits are disposed at the peripheral portion, thereby decreasing the difference in the amplitude amount between the central portion and the peripheral portion.