Piezoelectric Inertial Drive Stage With High-Stiffness Flexure
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Solution Overview
Problem
Current piezoelectric inertial drive stages face limitations in displacement range and performance due to low stiffness in flexure portions, which restricts traveling speed and axial force, making them less competitive in the market.
Innovation Solution
A compact piezoelectric inertial drive stage design featuring a high-stiffness flexure portion with parallel connection rods and adjustable parameters to enhance stiffness, allowing for fast response and high-frequency operation, thereby increasing traveling speed and axial force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a low-stiffness flexure portion (such as S-shaped resilient portion or tapered spring) is used in the piezoelectric inertial driver, then the structure is simpler and easier to manufacture, but the traveling speed and axial force are limited
Solution Approach 1:
The flexure portion is divided into multiple parallel connection rods instead of using a single continuous resilient member. This segmentation allows each rod to contribute to the overall stiffness while maintaining the flexure function, resolving the contradiction between simplicity and performance by distributing the structural function across multiple simple elements
Solution Approach 2:
The flexure portion uses a composite structure combining rigid connection rods with flexible joints, creating a mechanism that achieves high stiffness through geometric configuration rather than material properties alone. This resolves the contradiction by achieving high performance through structural design rather than requiring complex single-piece resilient members
2Ease of manufacture
If a low-stiffness flexure portion is used, then manufacturing is easier, but the response speed and operating frequency are reduced
Solution Approach 1:
By segmenting the flexure into multiple rigid connection rods connected by simple joints, the manufacturing process becomes simpler (each rod can be manufactured separately) while the parallel arrangement provides the necessary stiffness for high-frequency operation, resolving the contradiction between ease of manufacture and operating frequency
Solution Approach 2:
The design replaces traditional elastic deformation-based flexure (continuous resilient member) with a rigid-linkage-based flexure mechanism. This substitution maintains manufacturing simplicity while achieving higher stiffness and faster response through the rigid connection rods and geometric configuration
3Length of moving object
If conventional piezoelectric actuator structures are used, then the design is simpler, but the displacement range is limited to several millimeters
Solution Approach 1:
The piezoelectric inertial driver uses dynamic stick-slip motion between the friction portion and slider, where the friction portion alternates between sticking to and slipping from the slider surface. This dynamic mechanism converts small piezoelectric displacements into larger slider travels through inertial effects, resolving the contradiction between simple actuator structure and large displacement range
Solution Approach 2:
The system utilizes controlled vibrations and oscillations in the stick-slip driving mechanism, where rapid alternating sticking and slipping of the friction portion creates cumulative displacement in the slider. This vibrational approach enables large travel ranges from small piezoelectric actuator strokes without increasing structural 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 design achieves speeds up to 100mm/s and 10N axial pushing force, surpassing commercial products, making it competitive and attractive in the market.
Implementation Method 1
Based on inverse piezoelectric effect, piezoelectric actuators or motors could transfer electrical field into mechanical strain or movement
Implementation Method 2
The slider could achieve a small movement in a cycle of the driving of the piezoelectric element due to the inertia of the masses of the components involved
Data Source
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AI summary
Disclosed is a piezoelectric inertial drive stage including a piezoelectric inertial driver, a slider and a holder. The driver includes a mounting portion (1010) for the mounting on the holder, a friction portion (1050) coupling to the slider, a flexure portion (1030) between the mounting portion (1010) and a movement portion (1040), a piezoelectric element (1020) with a first end bonded to the mounting portion (1010) and a second end bonded to the movement portion (1040), the movement portion (1040) transferring the motion of the piezoelectric element (1020) to the friction portion (1050) to drive the slider.