MEMS Scanner Double Leverage for Non-Resonant Angular Displacement
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Solution Overview
Problem
Piezoelectric actuators used in scanning mirrors have limited motion outside of resonant frequencies, resulting in narrow displacement angles and difficulties in implementing scanning mirrors in display systems and other optical systems.
Innovation Solution
A MEMS scanner design featuring a first flexible arm with a thicker base and a second flexible arm extending in a reverse direction, both with piezoelectric thin films, allowing for increased motion and angular displacement of a mirror through double leverage configuration, compensating for low mobility of piezoelectric actuators outside resonant frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If piezoelectric actuators are used in scanning mirrors, then the mirror can be actuated, but the motion is limited outside of resonant frequencies resulting in narrow displacement angles
Solution Approach 1:
The patent introduces a second flexible arm extending in a reverse direction from the first flexible arm, creating a dual-arm configuration that adds a dimensional aspect to the actuation mechanism. This allows the mirror to achieve greater angular displacement by combining the motion contributions from both arms, effectively expanding the scanning angle range beyond what a single piezoelectric actuator could provide.
Solution Approach 2:
The patent divides the actuation system into two separate flexible arms, each with its own piezoelectric thin film, rather than using a single actuator. This segmentation allows independent control and motion contribution from each arm, enabling the mirror to achieve larger total displacement angles by summing the individual arm displacements.
2Device complexity
If a single flexible arm with piezoelectric actuator is used, then the structure is simple, but the angular displacement is limited
Solution Approach 1:
The patent extends the structure by adding a second flexible arm in the reverse direction, transforming a one-arm configuration into a two-arm configuration. This dimensional expansion allows the system to achieve greater angular displacement while maintaining relative structural simplicity through the symmetric arrangement of the two arms.
3Adaptability or versatility
If piezoelectric actuators operate outside resonant frequencies, then non-resonant scanning is enabled, but mobility is low resulting in limited motion
Solution Approach 1:
The patent segments the actuation function across two flexible arms with separate piezoelectric thin films. By dividing the actuation task, each arm can contribute to the total motion, effectively doubling the potential displacement range and improving mobility when operating outside resonant frequencies, thereby enabling effective non-resonant scanning.
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 MEMS scanner achieves a maximum angular displacement of 12° for the mirror, enhancing scanning capabilities in non-resonant applications without introducing unwanted twisting, thereby improving the performance of scanning mirrors in display and imaging systems.
Implementation Method 1
both with piezoelectric thin films, allowing for increased motion and angular displacement of a mirror
Data Source
AI summary
A MEMS scanner may include a first flexible arm extending substantially in a forward direction and a base connected to a proximal end of the first flexible arm, the base being thicker than the first flexible arm in a vertical direction. The MEMS scanner may further include a second flexible arm connected to a distal end of the first flexible arm, the second flexible arm extending substantially in a reverse direction. The MEMS scanner may further include a mirror coupled to a distal end of the second flexible arm. In one implementation, the MEMS scanner may be a non-resonant scanner.