MEMS Silicon Hinge and Slot-Cut Resonator for Vibratory Gyroscope
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Solution Overview
Problem
Existing disk resonator gyroscopes are sensitive to vibration and shock due to reduced stiffness when ring widths are minimized for improved tuning capability, leading to lower resonance frequencies and increased susceptibility to environmental disturbances.
Innovation Solution
The design incorporates 'Hinge and/or Slot' connection structures between concentric rings, making the joints as compliant as the remaining ring portions without reducing resonance frequency, allowing for reduced sensitivity to vibrations and shocks while maintaining high-Q performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ring width is reduced to improve tuning capability and resonance frequency adjustment, then tuning capability is improved, but stiffness is reduced dramatically making the resonator more susceptible to environmental vibrations and shocks
Solution Approach 1:
The patent applies local quality by creating hinge connection structures with selectively reduced thickness at specific locations where rings connect, while maintaining full thickness in other portions of the rings. This allows the connection regions to be more compliant for tuning purposes while the main ring structures retain their stiffness to resist environmental vibrations and shocks.
2Speed
If ring width is reduced to achieve lower resonance frequency, then resonance frequency is adjusted, but the resonator becomes more susceptible to environmental vibrations and shocks
Solution Approach 1:
The hinge connection structures implement local quality by reducing thickness only at the connection points between rings, allowing frequency adjustment through controlled compliance at these localized regions while the majority of the ring structure maintains its original thickness and stiffness to resist environmental disturbances.
3Adaptability or versatility
If compliant joints are created to improve tuning capability, then tuning capability is improved, but acceleration sensitivity increases
Solution Approach 1:
The patent resolves this contradiction by localizing the compliance to specific hinge connection regions through selective thickness reduction, while the main body of the rings maintains full thickness. This creates a balanced structure where tuning is achieved through the compliant hinges but the overall structural integrity and resistance to acceleration sensitivity is preserved by the thicker main ring portions.
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 MEMS silicon Hinge and Slot-cut Vibratory Gyroscope with reduced acceleration sensitivity and increased thermoelastic damping limited quality factor, enabling operation at similar frequencies with improved vibration insensitivity and thermal stability.
Implementation Method 1
making the joints between the rings as compliant as the remaining portions of the rings
Implementation Method 2
increased thermoelastic damping limited quality factor
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A resonant structure comprising at least two coaxial rings, wherein adjacent coaxial rings have adjacent peripheries and are attached together by a plurality of connection structures regularly arranged along said adjacent peripheries; and wherein a first ring has a first ring portion with a first radial thickness and a second ring portion, in a vicinity of a first connection structure, with a second radial thickness smaller than said first radial thickness.