MEMS Rate Sensor With Vacuum Cavity Damping Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Micro-Electro-Mechanical-Systems (MEMS) devices face challenges in increasing performance, reducing size, and decreasing cost, while also requiring more complex microsystems with greater computational power, which are not adequately addressed by existing technologies.
Innovation Solution
A MEMS rate sensor is configured over a CMOS substrate with a driver set and sensing elements for 3-axis rotational sensing, featuring low damping in driving masses and high damping in sensing masses, utilizing a single mask layer and single crystal silicon materials, and a vacuum cavity for improved performance and power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MEMS process technologies are used, then fabrication simplicity is maintained, but performance and computational power are insufficient
Solution Approach 1:
The device is segmented into distinct functional regions: a CMOS substrate layer for computational processing and a MEMS layer for sensing functions. This segmentation allows each layer to be optimized independently - the CMOS layer provides high computational power while the MEMS layer maintains fabrication simplicity through conventional processes.
Solution Approach 2:
The patent employs a composite structure combining CMOS semiconductor material with MEMS structural materials. This composite approach enables the integration of high-performance computational capabilities (from CMOS) with sensitive mechanical sensing (from MEMS), resolving the contradiction between performance requirements and fabrication simplicity.
2Volume of moving object
If device size is reduced, then integration density increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent transitions from planar 2D integration to 3D vertical stacking, with the MEMS structure built over the CMOS substrate. This dimensional change allows compact integration without proportionally increasing fabrication precision requirements, as the vertical dimension provides additional design space for tolerance management.
3Length of moving object
If driving electrical potential is increased, then oscillation amplitude increases, but power consumption increases
Solution Approach 1:
The patent optimizes the mechanical parameters of the MEMS structure, including proof mass geometry, suspension beam stiffness, and cavity pressure, to maximize oscillation amplitude efficiency. By carefully tuning these parameters, the device achieves high oscillation amplitude at low driving potentials, reducing power consumption while maintaining sensitive detection capability.
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 the power consumption and performance of MEMS rate sensors by achieving high oscillation amplitude with low driving electrical potential, while simplifying fabrication and reducing noise, resulting in a more stable and efficient MEMS device.
Implementation Method 1
low damping in driving masses... with low driving electrical potential to achieve high oscillation amplitude
Implementation Method 2
a vacuum cavity for improved performance and power efficiency
Implementation Method 3
high damping in sensing masses... ideal for a MEMS rate sensor design
Data Source
AI summary
A MEMS rate sensor device. In an embodiment, the sensor device includes a MEMS rate sensor configured overlying a CMOS substrate. The MEMS rate sensor can include a driver set, with four driver elements, and a sensor set, with six sensing elements, configured for 3-axis rotational sensing. This sensor architecture allows low damping in driving masses and high damping in sensing masses, which is ideal for a MEMS rate sensor design. Low driver damping is beneficial to MEMS rate power consumption and performance, with low driving electrical potential to achieve high oscillation amplitude.