MEMS Beam Electrode Resonance Layout for Wide-Range Force Sensing
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Solution Overview
Problem
Existing sensors using MEMS structures lack the ability to provide a wide dynamic range with high accuracy in detecting forces such as acceleration.
Innovation Solution
The sensor incorporates beams with different resonance characteristics by varying the mass, material, thickness, hole size and density, and layer structure of the beam electrodes, allowing for differential detection of vibration characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single beam structure is used for detection, then the device complexity is low, but the measurement precision and dynamic range are limited
Solution Approach 1:
The sensor is divided into multiple independent beam structures (first beam, second beam, third beam, fourth beam) with different resonance characteristics. Each beam acts as an independent detection element, allowing the sensor to measure a wider dynamic range through differential detection while maintaining manageable structural complexity through modular design
Solution Approach 2:
Each beam is designed with different local qualities - specifically different resonance frequencies achieved through varying mass, material, thickness, or geometry. This allows each beam to be optimized for specific detection ranges, with the first and third beams having first resonance characteristics and the second and fourth beams having second resonance characteristics, enabling high-precision detection across different acceleration magnitudes
2Adaptability or versatility
If beams with different resonance characteristics are used, then the dynamic range and measurement precision are improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent implements different resonance characteristics by changing physical parameters of the beam electrodes - specifically mass, material composition, thickness, and geometric dimensions. The first and third beams are designed with parameters yielding a first resonance frequency, while the second and fourth beams have parameters yielding a second resonance frequency, allowing wide dynamic range detection through differential measurement of these distinct resonant responses
Solution Approach 2:
The beam electrodes may utilize composite material structures with different mass densities and mechanical properties to achieve the required resonance frequency differentiation. This allows precise control over vibrational characteristics while maintaining compatibility with standard MEMS manufacturing processes, balancing manufacturing feasibility with performance requirements
3Reliability
If multiple beam electrodes with different characteristics are implemented, then temperature dependence is reduced and accuracy is improved, but the device complexity increases
Solution Approach 1:
The sensor employs segmented beam structures (four distinct beams) with alternating resonance characteristics. This segmentation enables differential detection where temperature-induced drift in one beam can be compensated by comparing against another beam with different resonance characteristics, improving temperature stability while maintaining a structured, manageable design
Solution Approach 2:
Different local qualities in terms of resonance frequency are assigned to different beams, creating a set of detection elements with complementary temperature dependencies. The first and third beams share similar local qualities, as do the second and fourth beams, allowing cross-validation and temperature compensation through differential measurement, thereby enhancing reliability without excessive 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
This design enables high-accuracy detection across a wide dynamic range with reduced temperature dependence, enhancing the sensor's performance.
Implementation Method 1
a first resonance frequency different from a second resonance frequency
Implementation Method 2
detecting changes in vibration characteristics of the first beam electrode and the second beam electrode
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3D
AI summary
According to one embodiment, a sensor includes an element section. The element section includes a first beam, a first beam electrode, a second beam, and a second beam electrode. The first beam includes a first portion, a first other portion, and a first intermediate portion between the first portion and the first other portion. The first beam electrode is connected to the first intermediate portion. The second beam includes a second portion, a second other portion, and a second intermediate portion between the second portion and the second other portion. The second beam electrode is connected to the second intermediate portion. The first and the second beam electrodes satisfy at least one of first to eighth conditions.