Piezoelectric Movable Structure for Large-Angle 2D Scanning
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Solution Overview
Problem
Existing movable devices do not effectively increase the deflection angle of the movable portion, limiting their scanning capabilities and efficiency.
Innovation Solution
A movable device with a silicon on insulator (SOI) substrate and piezoelectric actuators, featuring torsion bars and drive units with strategically designed openings and symmetrical configurations, allows for increased deflection angles and efficient oscillation through controlled voltage application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the aspect ratio of the dispersion surface is increased to more than four, then the enlargement ratio of the deflection angle is increased by more than four times, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent employs resonance vibration of the movable portion at a specific natural frequency to achieve large deflection angles. By utilizing the dynamic resonance characteristic of the structure, the system achieves high deflection angle enlargement without requiring complex mechanical amplification mechanisms, thus resolving the contradiction between performance and complexity.
Solution Approach 2:
The patent optimizes specific structural parameters including the aspect ratio of the movable portion (length-to-width ratio between 2-10), the position and dimensions of openings in drive units, and the thickness ratios of different layers. These parameter optimizations enable the structure to achieve resonance at desired frequencies with enhanced deflection angles while maintaining manufacturing feasibility.
2Productivity
If resonance vibration is used to increase deflection angle, then oscillation efficiency is improved, but stress concentration may occur at critical points
Solution Approach 1:
The patent introduces openings that divide the drive units and connection portions into multiple segments. This segmentation reduces stress concentration by distributing mechanical stresses across multiple paths and avoiding continuous stress flow through critical regions, while still maintaining the structural integrity needed for resonance vibration.
Solution Approach 2:
The patent applies different structural characteristics to different regions: the movable portion has specific aspect ratios for resonance, the drive units include openings for stress relief, and connection portions have optimized thicknesses. This localized optimization allows the structure to achieve both high oscillation efficiency and reduced stress concentration at critical points.
3Speed
If multiple openings are added to drive units and connection portions, then stress concentration is reduced and deflection angle is increased, but manufacturing complexity increases
Solution Approach 1:
The patent integrates multiple functions into unified structures: the openings in drive units simultaneously serve stress relief, weight reduction, and resonance frequency tuning purposes. The connection portions are designed as integrated elements that connect multiple components while incorporating stress-relief features, reducing the need for separate manufacturing steps and assembly operations.
4Productivity
If the movable portion is designed with specific aspect ratio for resonance, then oscillation amplitude is increased, but the device size increases
Solution Approach 1:
The patent optimizes the aspect ratio of the movable portion within a specific range (length-to-width ratio between 2-10) to achieve resonance at desired frequencies while controlling the overall size. By carefully selecting parameters within optimal ranges rather than using extreme values, the system achieves high oscillation amplitude without excessive device size increase.
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
Enhances the deflection angle and oscillation efficiency, reducing power consumption and overall device size while enabling two-dimensional scanning with improved drive efficiency and reduced stress concentration.
Implementation Method 1
A movable device with a silicon on insulator (SOI) substrate and piezoelectric actuators
Implementation Method 2
featuring torsion bars and drive units with strategically designed openings
Data Source
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AI summary
A movable device (13) includes a supporting portion (120); a movable portion (101) in the supporting portion, the movable portion (101) movable about a first rotation axis (1) and a second rotation axis (2) intersecting with the first rotation axis (1); a member (110a) between the movable portion (101) and the supporting portion (120) and connected to the movable portion (101) and the supporting portion (120) in a connection direction. The member (110a) includes: a drive unit (112a) configured to move the movable portion; and an opening (170) in a part of the drive unit (112a).