MEMS Sensor Asymmetric Mass Segmentation for Dynamic Range
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Solution Overview
Problem
Current sensors using MEMS structures face challenges in improving their characteristics, such as sensitivity and dynamic range, while maintaining high accuracy and temperature stability.
Innovation Solution
The sensor design incorporates a unique configuration with a first and second movable portion, including beams and conductive portions with specific extensions and holes, which differ in mass and area, to detect acceleration by resonant frequency differences, and includes a circuit controller for signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional MEMS sensor structure is used, then the device complexity is low, but the sensitivity and dynamic range are limited
Solution Approach 1:
The movable portion is divided into first and second movable portions with different masses, each having distinct resonant frequencies. This segmentation allows the sensor to detect a wider range of acceleration values by utilizing the resonant frequency differences between the two portions, thereby improving sensitivity and dynamic range without requiring multiple separate sensors.
Solution Approach 2:
The first and second movable portions are designed with asymmetric mass distribution, where the first movable portion has a different mass than the second movable portion. This asymmetry creates distinct resonant frequencies that enable the sensor to differentiate between small and large acceleration values, enhancing measurement precision across a broader dynamic range.
2Adaptability or versatility
If the movable portion mass is increased to improve dynamic range, then the acceleration detection range expands, but the resonant frequency decreases affecting sensitivity
Solution Approach 1:
By segmenting the movable portion into two distinct masses, the sensor can utilize the resonant frequency of the lighter portion for high-sensitivity detection of small accelerations, while the heavier portion responds to larger accelerations. This segmentation resolves the trade-off by allowing both sensitivity and dynamic range to be optimized simultaneously through differential resonance detection.
Solution Approach 2:
The invention changes the mass parameter of the movable portion by introducing two different masses instead of a single uniform mass. This parameter change enables the system to achieve both high resonant frequency (for sensitivity) with the lighter portion and expanded dynamic range (with the heavier portion) without the traditional compromise.
3Stability of the object's composition
If temperature compensation mechanisms are added to maintain temperature stability, then the temperature stability improves, but the device complexity increases
Solution Approach 1:
The sensor utilizes the inherent resonant frequency characteristics of the two movable portions to self-compensate for temperature variations. By monitoring the resonant frequency differences between the first and second movable portions, the system can detect and compensate for temperature drift without requiring external temperature sensors or complex compensation circuits, thereby maintaining temperature stability while avoiding increased device 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 configuration enhances sensitivity, expands the dynamic range, and maintains high accuracy and temperature stability, allowing for improved sensor characteristics.
Implementation Method 1
detect acceleration by resonant frequency differences
Data Source
AI summary
According to one embodiment, a sensor a sensor includes a base, a first support portion fixed to the base, and a first movable portion supported by the first support portion. The first movable portion includes first and second movable base portions, a connecting base portion, first and second movable beams, and first and second movable conductive portions. The first movable beam includes a first beam end portion, a first beam other end portion, and a first beam intermediate portion. The second movable beam includes a second beam end portion, a second beam other end portion, and a second beam intermediate portion. The first movable conductive portion includes a first crossing conductive portion, a first extending conductive portion, and a first other extending conductive portion. The second movable conductive portion includes a second crossing conductive portion, a second extending conductive portion, and a second other extending conductive portion.