MEMS Inertial Sensor with Electrostatic Anchoring for Dual-Range Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MEMS inertial sensors with dual detection structures for low and high accelerations require complex control circuitry and increased integration area, leading to higher manufacturing costs and reduced portability.
Innovation Solution
A MEMS device with a movable structure and elastic support elements, featuring control masses and elastic coupling elements, allows for dual operating states to detect both low and high accelerations using capacitive detection and electrostatic forces, optimizing sensitivity and full scale range without the need for multiple detection structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If two separate movable detection structures are integrated in the same MEMS device to detect both low and high accelerations, then the detection capability for both low and high accelerations is improved, but the device complexity, integration area, and manufacturing cost increase
Solution Approach 1:
The patent applies the dynamics principle by making the movable structure's effective mass dynamically adjustable through electrostatic actuation. The control mass can be electrically positioned to either couple with or decouple from the detection mass, allowing the system to transition between high-sensitivity mode (detection mass only) and high-range mode (detection mass + control mass). This dynamic reconfiguration enables a single physical structure to serve dual detection functions without requiring separate dedicated structures for each function.
Solution Approach 2:
The patent implements multi-functionality by designing a single movable structure that can perform both low-acceleration detection and high-acceleration detection through electrostatic control. The control mass, when electrically actuated, modifies the effective mass of the detection structure, allowing one physical component to fulfill multiple detection roles that would traditionally require separate dedicated structures.
2Adaptability or versatility
If two separate movable detection structures are integrated in the same MEMS device, then the detection capability for both low and high accelerations is improved, but the integration area increases
Solution Approach 1:
The patent applies the merging principle by combining the detection function and the mass-adjustment function into a single integrated movable structure. Instead of having separate detection structures for low and high acceleration ranges, the design merges these functions into one structure where the control mass can be electrically positioned to modify the effective mass, thereby reducing the overall integration area while maintaining dual detection capability.
3Adaptability or versatility
If two separate movable detection structures are integrated in the same MEMS device, then the detection capability for both low and high accelerations is improved, but the manufacturing cost increases
Solution Approach 1:
The patent reduces manufacturing cost by merging dual detection functions into a single movable structure with electrostatic control, eliminating the need for separate dedicated structures for low and high acceleration detection. This integration reduces the number of components, simplifies the manufacturing process, and lowers overall device cost while maintaining the capability to detect both low and high accelerations.
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
The device achieves high detection sensitivity for low accelerations and a greater full scale range for high accelerations while minimizing complexity and cost, enhancing portability and manufacturing efficiency.
Implementation Method 1
a control mass (29A, 29B; 229) and a control electrode (33A, 33B; 233) fixed to the substrate (21), the control electrode being capacitively coupled to the control mass (29A, 29B; 229) and configured to generate an electrostatic force on the control mass (29A, 29B; 229) along the first direction (Y)
Implementation Method 2
a first elastic group (30A, 30B; 230) mechanically coupled between the first mass (28) and the second mass (29A, 29B; 229), the first elastic group being compliant along a first direction (Y), a second elastic group (23; 123A, 123B) mechanically coupled between the substrate (21) and the movable structure (22; 122; 222), the second elastic group being compliant along the first direction (Y)
Implementation Method 3
The MEMS device (20; 120; 220) further comprises a detection structure (50) configured to detect a movement of the first mass (28) along the first direction (Y)
Data Source
AI summary
The MEMS device is formed by a substrate and a movable structure suspended on the substrate. The movable structure has a first mass, a second mass and a first elastic group mechanically coupled between the first and the second masses. The first elastic group is compliant along a first direction. The first mass is configured to move with respect to the substrate along the first direction. The MEMS device also has a second elastic group mechanically coupled between the substrate and the movable structure and compliant along the first direction; and an anchoring control structure fixed to the substrate, capacitively coupled to the second mass and configured to exert an electrostatic force on the second mass along the first direction. The anchoring control structure controls the MEMS device in a first operating state, wherein the second mass is free to move with respect to the substrate along the first direction, and in a second operating state, wherein the anchoring control structure applies a pull-in force on the second mass which anchors the second mass to the anchoring structure.