MEMS Mirror Comb Actuator Structure for Vibration-Resistant Tilting
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Solution Overview
Problem
Traditional MEMS devices with two-layer comb actuators struggle to provide sufficient driving torque and maintain deflection angles under operational vibrations, especially in solid-state LIDAR systems, due to misalignment of the hinge pivot point with the mirror's mass center, leading to reduced functionality.
Innovation Solution
Implementing a three-layer comb actuator structure and a two-layer hinge with a pivot point aligned with the mirror's mass center to enhance driving torque and resist vibrations, allowing for robust tilting and deflection of the mirror in MEMS devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a two-layer comb actuator structure is used, then the device complexity is reduced, but the driving torque is insufficient and the device cannot maintain deflection angles under operational vibrations
Solution Approach 1:
The patent transitions from a two-layer comb actuator structure to a three-layer comb actuator structure, adding a vertical dimension to the actuator design. This dimensional expansion enables the generation of sufficient driving torque while maintaining a compact form factor, directly resolving the contradiction between force output and structural complexity.
Solution Approach 2:
The comb actuator is divided into three distinct layers, with each layer performing specific functional roles. The first layer provides structural support, the second layer contains the comb teeth for torque generation, and the third layer offers additional mechanical advantage. This segmentation allows each layer to be optimized independently, achieving high torque output without excessive overall complexity.
2Reliability
If the hinge pivot point is not aligned with the mirror's mass center, then the manufacturing precision is easier to achieve, but the device cannot resist operational vibrations effectively
Solution Approach 1:
The patent positions the hinge pivot point at the mirror's mass center, creating a balanced configuration where the mirror's weight is evenly distributed around the pivot. This counterbalancing effect naturally resists operational vibrations without requiring additional active control mechanisms, thereby improving vibration resistance while maintaining reasonable manufacturing tolerances.
Solution Approach 2:
The invention changes the critical parameter of pivot point location from an arbitrary position to a specific position coinciding with the mirror's mass center. This parameter change transforms the system's dynamic characteristics, enabling passive vibration resistance through proper mass distribution rather than requiring active compensation.
3Reliability
If a three-layer comb actuator structure is implemented, then the driving torque is sufficient and deflection angles are maintained under vibrations, but the device complexity increases
Solution Approach 1:
The three-layer comb actuator structure is designed with nested components where the first layer provides a structural framework, the second layer inserts comb teeth within that framework, and the third layer adds reinforcement elements. This nesting approach maximizes functional density while minimizing the overall volume and external complexity of the actuator assembly.
Solution Approach 2:
Each layer of the three-layer comb actuator serves multiple functions: the first layer provides both structural support and mechanical mounting, the second layer generates torque through comb tooth interaction while also providing structural rigidity, and the third layer offers both reinforcement and electrical isolation. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in overall device complexity.
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 solution provides increased resistance to operational vibrations, ensuring stable and robust functionality of MEMS devices and solid-state LIDAR systems with improved deflection angles and resistance to mechanical wear.
Implementation Method 1
a comb actuator structure associated with a first hinge of the set of first hinges, wherein the first comb actuator structure includes a rotor comb actuator that forms part of the second layer and two stator comb actuators that respectively form part of the first layer and part of the third layer
Data Source
AI summary
A micro-sized optical device may comprise a mirror suspended on a set of hinges that are mounted to the substrate and that are configured to tilt the mirror about an axis, wherein a hinge of the set of hinges is a two-layer structure with a pivot point that aligns with a mass center of the mirror; and a three-layer comb actuator structure associated with the hinge of the set of hinges, wherein the three-layer comb actuator structure includes a rotor comb actuator, a first stator comb actuator, and a second stator comb actuator.