3D MEMS Resonator Shells With Selective Openings for High-Q Gyroscopes
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Solution Overview
Problem
Current methods for fabricating three-dimensional microstructures, particularly from high-melting-temperature materials like fused silica, face challenges in achieving high precision and quality due to expensive and time-consuming processes, such as mechanical grinding and laser ablation, which limit the production of micro- and millimeter-scale structures with high mechanical quality factors for applications like gyroscopes.
Innovation Solution
The development of techniques to create three-dimensional microstructures with selectively removed regions using methods like blowtorch molding and chemical etching, allowing for the formation of structures with high quality factors and improved resonant frequencies, enabling the fabrication of micro- and millimeter-scale gyroscopes with enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical grinding and laser ablation are used to fabricate three-dimensional microstructures, then manufacturing precision and quality can be achieved, but production cost and time increase significantly
Solution Approach 1:
The patent replaces mechanical grinding processes with chemical etching methods. Specifically, it uses sacrificial layers that are selectively removed through chemical etchants, allowing three-dimensional microstructures to be formed without mechanical contact. This substitution eliminates the time-consuming mechanical grinding step while maintaining fabrication precision through controlled chemical reactions.
Solution Approach 2:
The patent introduces sacrificial layers as intermediary materials that facilitate the formation of three-dimensional microstructures. These sacrificial layers are deposited on the substrate, patterned to define the desired structure, and then selectively removed through chemical etching. This intermediary approach enables precise structure formation without direct mechanical manipulation of the final structure.
2Manufacturing precision
If mechanical grinding and laser ablation are used to fabricate three-dimensional microstructures, then manufacturing precision can be improved, but production cost increases
Solution Approach 1:
The patent replaces expensive mechanical grinding equipment and laser ablation systems with simpler chemical etching processes. The chemical etching method uses standard semiconductor fabrication equipment and chemical solutions, significantly reducing capital equipment costs while achieving comparable or superior precision through controlled chemical reactions and sacrificial layer removal.
Solution Approach 2:
The patent employs disposable sacrificial layers that are intentionally designed to be temporary and easily removable. These sacrificial layers serve their purpose during fabrication and are then completely removed through chemical etching, leaving no waste from expensive mechanical processing. This approach converts expensive durable equipment costs into cheaper consumable material costs.
3Reliability
If conventional fabrication methods are used, then structures can be produced, but mechanical quality factors and resonant frequencies cannot be optimized
Solution Approach 1:
The patent applies local quality by selectively removing material from specific regions of the three-dimensional microstructure through patterned sacrificial layers. This allows different regions of the structure to have optimized properties - some regions maintain full thickness for structural integrity and high Q-factor, while other regions have selective material removal to tune resonant frequencies and reduce mass, achieving localized optimization of mechanical properties.
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
These techniques enable the production of high-quality three-dimensional microstructures with improved mechanical quality factors, reducing production costs and time, and enhancing the performance of gyroscopes by allowing for precise tuning of resonant frequencies and reduced energy loss.
Implementation Method 1
blowtorch molding
Implementation Method 2
high-melting-temperature materials like fused silica
Implementation Method 3
chemical etching
Implementation Method 4
improved resonant frequencies, enabling the fabrication of micro- and millimeter-scale gyroscopes with enhanced performance
Data Source
AI summary
Three-dimensional (3D) micro-scale shells are presented with selectively removed regions/openings and which can be used in sensors and actuators, including gyroscopes. Example shells consisting of a suspended ring-shaped resonator that is supported using multiple beams that are not in the plane of the ring and are attached to a support post can be formed. Shells with various sizes and geometries of selectively removed regions and openings allow the creation of micro electromechanical systems (MEMS) sensors and actuators with a wide range of engineered mechanical and electrical properties. These shells can be used to form stacked 3D structures for various types of MEMS sensor and actuator devices, such as resonant gyroscopes, with sense and drive electrodes that conform to the curved profile of the resonant shell using for gyroscopes. 3D shells formed from a starting parent substrate are released and separated from their parent substrate using a number of techniques.