Crystal-Oriented MEMS Resonator for High-Q Strain Sensing
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Solution Overview
Problem
Existing resonators in MEMS devices face challenges in achieving high sensitivity and frequency band selectivity due to limitations in signal output and Q-factor, particularly when measuring external inputs like stress and pressure, as they often result in inefficient strain sensing and broad resonance frequency bands.
Innovation Solution
The resonator is designed to extend in specific crystal orientations of single crystal silicon based on Young's modulus and Poisson's ratio, optimizing its structure to have a smallest effective modulus during strain, thereby enhancing the sensing layer's stress distribution and output, and patterning techniques are used to align the resonator at precise angles relative to the crystal plane for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resonators are manufactured using conventional MEMS techniques on silicon substrates, then they can be integrated into various devices, but they exhibit broad resonance frequency bands and insufficient Q-factor
Solution Approach 1:
The patent changes the material parameter from conventional silicon to single crystal silicon with specific crystal orientations. By selecting <110> or <100> oriented single crystal silicon, the resonator achieves enhanced Q-factor and narrowed resonance frequency bands due to the superior mechanical properties and lower internal damping of single crystal structures compared to polycrystalline silicon.
Solution Approach 2:
The patent applies different crystal orientations to different regions or aspects of the resonator structure. By orienting the single crystal silicon in specific directions (<110> or <100>), the resonator achieves optimized stress distribution and vibration characteristics in critical areas, leading to improved Q-factor and frequency selectivity.
2Measurement precision
If the resonator structure is optimized for high Q-factor using single crystal silicon with specific orientations, then measurement sensitivity improves, but manufacturing complexity increases
Solution Approach 1:
The patent performs preliminary action by pre-selecting and preparing single crystal silicon wafers with specific orientations (<110> or <100>) before resonator fabrication. This upfront material selection ensures the desired mechanical properties are built into the base material, simplifying subsequent processing steps and reducing the need for complex post-fabrication adjustments.
Solution Approach 2:
The patent replaces conventional silicon-based resonator structures with single crystal silicon resonators that utilize the material's inherent anisotropic mechanical properties. This substitution eliminates the need for complex structural modifications or additional components to achieve high Q-factor, as the single crystal material itself provides the necessary performance characteristics.
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 approach results in a high Q mechanical resonator with improved signal output and frequency band selectivity, enabling enhanced measurement sensitivity and resolution for external inputs, and is applicable to sensors like mechanical filters and acoustic sensors.
Implementation Method 1
the resonator extends in a crystal orientation determined based on at least one a from among a Young's modulus and a Poisson's ratio
Implementation Method 2
the portion of a sensing layer among all the stress generated in the entire composite layer may be increased. An output of the sensor structure may therefore be improved or even maximized
Implementation Method 3
Resonators are devices that oscillate in a certain frequency band
Data Source
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AI summary
Provided are a resonator, a method of manufacturing the resonator, and a strain sensor and a sensor array including the resonator. The resonator is provided to extend in a lengthwise direction from a support. The resonator includes a single crystal material and is provided to extend in a crystal orientation that satisfies at least one from among a Young's modulus and a Poisson's ratio, from among crystal orientations of the single crystal material.