MEMS Mirror Flexure Connector Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MEMS mirror assemblies face challenges in scaling to smaller dimensions due to increased hinge spring forces per mirror area, leading to higher external forces required for movement, which results in stress, strain, reduced control, and micromirror distortion.
Innovation Solution
The optical element assembly features a unique connector assembly with flexure assemblies that allow for kinematic coupling of optical elements to a base, enabling precise movement with reduced distortion and stiction, and scalable design, using a double flexure arrangement to balance electrical and mechanical forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If MEMS mirror assemblies are scaled to smaller dimensions, then device size is reduced, but hinge spring forces per mirror area increase leading to higher external forces required for movement
Solution Approach 1:
The mirror assembly is divided into multiple independently controllable micromirrors, each with its own support structure. This segmentation allows each micromirror to be moved with reduced force compared to moving a single large mirror, as the hinge spring forces are distributed across multiple smaller units rather than concentrated in one large structure.
Solution Approach 2:
The patent employs flexible support structures and thin film materials in the hinge and suspension mechanisms. These flexible elements reduce the stiffness of the connection between micromirrors and the substrate, thereby reducing the hinge spring forces that oppose mirror movement. The flexible films allow for easier actuation while maintaining structural integrity.
2Ease of operation
If higher external forces are applied to move scaled-down mirrors, then movement is achieved, but stress and strain increase leading to reduced control and micromirror distortion
Solution Approach 1:
The patent optimizes the physical parameters of the micromirrors and their support structures, including thickness, material composition, and geometric configuration. By carefully selecting these parameters, the design achieves a balance where the mirrors are sufficiently lightweight and compliant for easy actuation, yet maintain adequate structural strength to prevent distortion under applied forces.
Solution Approach 2:
The support structures are designed to provide counterbalancing forces that offset the hinge spring forces during mirror actuation. This counterweight effect reduces the net external force required to move the mirrors, thereby minimizing stress and strain on the micromirror structures while maintaining precise control over their movement.
3Device complexity
If traditional connection methods are used for optical elements, then structural simplicity is maintained, but distortion and stiction increase during movement
Solution Approach 1:
The connector assembly incorporates flexible film elements that allow the optical elements to move smoothly without excessive friction or stiction. These flexible films provide a low-friction interface between moving and stationary components, enabling precise positioning while reducing the forces required for actuation and minimizing distortion during movement.
Solution Approach 2:
The connector assembly introduces intermediary flexible elements between the optical elements and the rigid support structure. These intermediaries act as mediators that decouple the rigid constraints from the moving optical elements, allowing for smooth, low-friction movement while maintaining precise positional control and reducing distortion.
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 design allows for precise control of optical element position with reduced stress and distortion, enabling efficient beam shaping and steering while maintaining scalability and minimizing stiction, thus overcoming the limitations of traditional MEMS mirror assemblies.
Implementation Method 1
a first flexure assembly having an element flexure and a base flexure
Data Source
AI summary
An optical element assembly includes a base, and an element unit. The element unit includes (i) an optical element having an element central axis and an element perimeter; and (ii) an element connector assembly that couples the optical element to the base, the element connector assembly including a flexure assembly having an element flexure and a base flexure. A distal end of the element flexure is coupled to the optical element near the element perimeter, a distal end of the base flexure is coupled to the base, and a proximal end of the element flexure is coupled to a proximal end of the base flexure near the element central axis.