Showing papers on "Piezoelectric motor published in 2022"

Performance Improvement of Micro-Ultrasonic Motors Using the Thickness Shear Mode Piezoelectric Elements

Abstract: • Thickness shear mode makes the micromotor suitable for operating with higher energy efficiency than conventional micromotors. • An efficiency of 2.1% and a torque of 40 µNm are 3–4 times larger than those of a micromotor based on area expansion mode. • The proposed motor is the most powerful micromotor in 1–2 millimeter-scale actuators. We propose a one-millimeter-scale traveling-wave ultrasonic motor that uses a thickness shear mode (15-mode) piezoelectric elements with a high shear piezoelectric coefficient. This thickness shear mode makes the micromotor suitable for operating with higher energy efficiency than conventional micromotors and enables a low voltage operation and a high torque generation. In this study, we build a thickness shear mode-driven micro-ultrasonic motor and demonstrate the improvement in motor performance. A micromotor comprising a cube with a side length of 1 mm and four piezoelectric plates is fabricated, and its dynamic and static characteristics are evaluated experimentally. With an optimal preload mechanism, the micromotor obtains unprecedented performance measures: an efficiency of 2.1% and a torque of 40 µNm, which are 3–4 times larger than those of a comparable micromotor using typical expansion mode (31-mode) piezoelectric elements. Currently, the proposed motor is the most powerful micromotor in 1–2 millimeter-scale actuators and represents a new benchmark for micromotors.

Design and experimental evaluation of an inchworm motor driven by bender-type piezoelectric actuators

Abstract: Abstract Piezoelectric actuators (PEAs) are widely used in ultra-precision detection platforms where nano-precision and non-magnetic features are required. With the development of the semiconductor industry, actuators develop toward the tendency of smaller size, higher precision, and longer travel. However, these demands are difficult to meet merely by virtue of a single piezoelectric actuator or a simple structured inchworm piezo motor, which makes it necessary to develop a new drive mode following a different drive principle. In this paper, a novel inchworm piezo motor with bender-type PEAs in phalanx distribution was proposed, which facilitates in reducing the dimension of the motor and enhances the performance and stability of the piezo motor. For the purpose of accommodating the bender-type PEAs and providing the preloads to the bender-type PEAs, a flexible mechanism housing was designed and the modal analysis was finished, avoid resonance and reduce structural vibration. Experimental results show that the resolution of the developed motor is 2 nm or less under the laser interference with an adoption rate of 10 MHz and a resolution of 0.1 nm, while the maximum stroke is over 19 mm at the constant speed of 2.3 mm s −1 , and the maximum output force is 41.6 N.

Design, simulation, and motion characteristics of a novel impact piezoelectric actuator using double stators

Abstract: Abstract This study presents a novel impact piezoelectric motor that excites double stators through a sinusoidal signal. A sawtooth signal drives the traditional impact piezoelectric actuator, and its working frequency is limited by the resonant frequency. This study uses sine signals to drive the double stators to produce a sinusoidal vibration. The sinusoidal vibration of different frequencies and amplitudes are synthesised into a sawtooth vibration on the stage plate. The directional movement of the slider is realised using the vibration of the stage plate to drive the slider. This structure reduces the space required for the piezoelectric actuator to work. The working principle of the motor is discussed, and the structure is constructed. The dynamics model of the whole system is established on the based of the dynamics model of the actuator and the LuGre friction model. Moreover, the dynamics model was simulated and analysed through MATLAB/Simulink. The prototype is fabricated and tested. Experimental results confirm the effectiveness of using sinusoidal signals to drive the piezoelectric actuator, and the motion process of the piezoelectric motor is consistent with the theoretical analysis. The maximum speed of the piezoelectric actuator is 5.54 mm s −1 , and the resolution is 0.72 μ m. This study provides an effective driving method for the quasi-static piezoelectric motor to improve the working frequency.

Miniaturized electromechanical devices with multi-vibration modes achieved by orderly stacked structure with piezoelectric strain units

Abstract: Piezoelectric devices based on a variety of vibration modes are widely utilized in high-tech fields to make a conversion between mechanical and electrical energies. The excitation of single or coupled vibration modes of piezoelectric devices is mainly related to the structure and property of piezoelectric materials. However, for the generally used piezoelectric materials, e.g., lead zirconate titanate ceramics, most of piezoelectric coefficients in the piezoelectric matrix are equal to zero, resulting in many piezoelectric vibration modes cannot be excited, which hinders the design of piezoelectric devices. In this work, an orderly stacked structure with piezoelectric strain units is proposed to achieve all nonzero piezoelectric coefficients, and consequently generate artificially coupled multi-vibration modes with ultrahigh strains. As an example, an orderly stacked structure with two piezoelectric strain units stator, corresponding to 31-36 coupled vibration mode, was designed and fabricated. Based on this orderly stacked structure with two piezoelectric strain units stator, we made a miniature ultrasonic motor (5 mmLength × 1.3 mmHeight × 1.06 mmWidth). Due to the ultrahigh strain of the 31-36 coupled vibration mode, the velocity per volume of the motor reached 4.66 s-1 mm-2. Furthermore, its moving resolution is around 3 nm, which is two orders higher than that of other piezoelectric motors. This work sheds a light on optimizing the performance of state-of-the-art electromechanical devices and may inspire new devices based on multi-vibration modes.

A Rotary-Linear Ultrasonic Motor Using MnO2-Doped (Ba0.97Ca0.03)(Ti0.96Sn0.005Hf0.035)O3 Lead-Free Piezoelectric Ceramics with Improved Curie Temperature and Temperature Stability

Abstract: In this work, a cylindrical lead-free rotary-linear ultrasonic motor was attached to piezoelectric plates of MnO2-doped (Ba0.97Ca0.03)(Ti0.96Sn0.005Hf0.035)O3 ceramics using the first bending vibration to pull a thread output shaft of the interior of a stator. The effect of the proposed ceramics’ d33 and Qm values are the key factors for ultrasonic motors. Therefore, MnO2-doped (Ba0.97Ca0.03)(Ti0.96Sn0.005Hf0.035)O3 lead-free piezoelectric ceramics with high values of d33 = 230 pC/N, Qm = 340.8 and a good temperature stability of their dielectric and piezoelectric properties are suitable for application to linear piezoelectric motors. The structure of the linear piezoelectric motor was simulated and fabricated by Finite Element Analysis. The characteristics of linear piezoelectric motors were also studied. The output characteristics of the lead-free piezoelectric motor were a left-pull velocity = 3.21 mm/s, a right-pull velocity = 3.39 mm/s, an up-pull velocity = 2.56 mm/s and a force >2 N at 39.09 kHz for an input voltage of approximately 200 Vp-p (peak to peak). These results are comparable to those for a lead-based piezoelectric motor that uses PZT-4 ceramics. The proposed lead-free piezoelectric motors were successfully fabricated and used to pull a 0.5 mL commercial insulin syringe.

Non-resonant piezoelectric linear motor with alternating normal contact force.

Abstract: A non-resonant piezoelectric linear motor with alternating normal contact force is developed to realize a piezoelectric linear motor with high precision, large stroke, and strong thrust. The motor employs four piezoelectric stacks to excite the non-resonant state vibration of two driving feet, which alternately push the mover to generate unidirectional motion. Through the analysis of the working principle of the motor, the structure of the motor is designed and manufactured. The test results show the feasibility of the motor. Furthermore, the operating results show that the flatness of the contact surface strongly affects the performance of the motor. The design criteria of the motor are proposed, thus providing a basis for the optimization of the motor.

Resonant-type rotating piezoelectric motor with inchworm-inertia composite impact.

Abstract: A resonant-type rotating piezoelectric motor with inchworm-inertia composite impact was designed and manufactured. It mainly comprises a stator, rotor, support shaft, and frame. The motor stator includes a clamp, driver, central connecting block, preload structure, and other auxiliary mechanisms. The clamp and driver of the motor work in a resonant state. The motor structure was optimized by using the finite element software COMSOL 5.2. Through the finite element simulation analysis, the first-order bending vibration of the clamp and the driver was selected as the working mode, and the consistency of the resonance frequency coupling was optimized and adjusted. By coordinating the bending vibration of the clamp and driver in the vertical staggered direction, the clamping foot drives the rotor to realize the unidirectional continuous rotation. The motor prototype was designed and processed, while the experimental device platform was established to verify the working principle of the motor, and the comprehensive performance of the motor was analyzed and tested. When the input driving voltage was 240 VP-P, the driving frequency was 161 Hz, and the preload torque of the motor was 6.9 N mm, the maximum no-load speed of the motor reached 3.23 rad/s and the maximum load torque reached 10.35 N mm. Under the same conditions, the maximum resolution of the motor rotation angle was 0.69°.

Design and characteristic analysis of multi-degree-of-freedom ultrasonic motor based on spherical stator.

Abstract: The multidimensional motion ultrasonic motor with a single spherical stator is studied in this paper. It has the characteristics of miniaturization and can be used in precision motion applications. By bonding six identical pieces of piezoelectric ceramic onto the stator and applying the voltage signal of high frequency, the deformation of the inverse piezoelectric effect is used to excite the stator yaw vibration mode. The orthogonal superposition of the modes of the spherical stator on the driving foot produces elliptical trajectory around X, Y, and Z directions by different excitation methods. According to the yaw vibration mode of the spherical stator, 12 driving feet are designed to drive the rotation of the spherical rotor. The structure and mechanical characteristics of the motor are simulated by using simulation software, and the transient response of the stator driving foot was obtained, which proved its feasibility. Finally, the output performance of the motor in actual operation is given through experiments, which provides a new reference scheme in the field of precise multi-degree-of-freedom motion. At a voltage of 100 V and a frequency of 26.7 kHz, the prototype has a no-load speed of 73, 70, and 114 rpm around X, Y, and Z axes, respectively.

A Linear Ultrasonic Motor Based on Coupling Vibration Mode

Abstract: A coupled linear ultrasonic motor (LUSM) based on an eccentric constraint was proposed. Two pieces of oblique piezoelectric ceramics were arranged at each end of the elastomer, and the polarization direction of the ceramics was vertically upward. Using the tilting characteristics of the piezoelectric ceramics, the two ends of the fixed piezoelectric ceramics formed an eccentric restraint on the motor, providing conditions for the motor to generate coupled modes. When the elastomer of the motor generated the coupling vibration, the motion trajectories of the driving feet ends were oblique straight lines, and the oblique straight-line motion trajectories of the upper and lower driving feet ends were in opposite directions, driving the upper and lower sliders to run simultaneously. The stator parameters were optimized by using ANSYS to obtain larger amplitudes for the ends of the driving feet in both X and Z directions. The structure and operation principle of the motor are explained in detail. A prototype was fabricated to study the arrangement scheme with fixed constraints at the ends of the motor. The frequency–velocity characteristics, voltage–velocity characteristics, and mechanical characteristics of the motor were tested. The no-load speed and maximum output power were measured to be 45.9 mm/s and 3.24 mW.

Design and development of a novel piezoelectric caudal fin-like underwater thruster with a single vibration mode.

Abstract: The flapping-motion of the caudal fin allows the fish to swim with high efficiency and mobility, particularly in terms of persistence, propulsion, and acceleration. This has led to theoretical and practical research on the development of robotic caudal fin thrusters that offer similar properties and performance. However, the current caudal fin thrusters are driven by electromagnetic motors, which require a transmission system that makes them difficult to miniaturize, and need protection against water intrusion. To address these issues, this paper proposes a novel piezoelectric caudal fin thruster with a fully open structure that has no chambers in any of its parts. The converse, piezoelectric effect and direct friction drive principle are used to make a rotation unit for the piezoelectric actuator drive and achieve a reciprocating motion that makes the caudal fin flap. The proposed piezoelectric caudal fin thruster has an open and simple structure. It has a weight of 30 g, a length of 89 mm, and a thrust of 0.07 N. It is easy to miniaturize and is lighter, smaller, and more efficient than previously reported caudal fin thrusters that were based on ionic polymer-metal composites and shape memory alloys. Experimental results verified the effectiveness of the proposed design, which can be easily scaled up or down in size depending on the operating situation.

Bionic Type Piezoelectric Actuators

Abstract: Piezoelectric actuators have been applied in many research and industrial fields. However, how to improve the working performance of piezoelectric actuators is still a hot issue. Up to now, many new motion principles have been developed for new piezoelectric actuators. The bionic type piezoelectric actuator is a kind of the novel piezoelectric actuators, and it imitates the motion style of different creatures in nature to overcome the limitation of traditional piezoelectric actuators. Bionic type piezoelectric actuators are able to achieve large working stroke or large output force, which is of great significance for the development of piezoelectric actuators. The principle, design, and future of some bionic type piezoelectric actuators are discussed in this chapter.

A Linear Ultrasonic Motor Using Longitudinal Vibration

Abstract: This study presents a linear ultrasonic motor. The structure is symmetrical and two groups of piezoelectric ceramics (PZT-8) are arranged along an axis. This way can make the motor structure compact. Operation principle of this motor is analyzed. Make and test a prototype to verify the feasibility of the principle. The experimental results show that the maximum no-load speed of the motor is 1289mm/s under the excitation of electrical signal with frequency of 29.96 kHz and voltage of 300VP-P.

5DOF planar – rotary motion piezoelectric robot

Abstract: Abstract A novel resonant type five degrees of freedom (5DOF) mobile piezoelectric robot is proposed and analysed. The piezoelectric robot performs unlimited linear working motion in the plane and rotates the positioning table or sphere about three axes independently. The piezorobot can be used for precise positioning or transportation of small objects and make complicated locomotion trajectories. The piezoelectric robot is designed as a compound structure and includes a piezoelectric ring and a special ring-shaped bronze layer. Electrodes of the piezoelectric ring are divided into six equal sections. Excitation of the piezoelectric robot is performed by using a single switched harmonic signal applied to the particular electrode. The operation principle of the piezoelectric robot is based on the excitation of the third radial vibration mode of the piezoelectric ring. The numerical and experimental study was performed, and the operating principle was validated. The maximum linear velocity of 18.8 mm/s and rotational speed of 31.3 rpm were achieved when load of 25.1g and excitation voltage of 200 V p-p were applied.

Modal Analysis of Piezoelectric Materials Based on Scanning Laser Vibration Measurement

Abstract: Piezoelectric material is a kind of intelligent material that can transform mechanical energy and electrical energy. It has formed a huge industry with a market scale of nearly 10 billion US dollars per year. Its application range is from mobile phones and other household electronic products to aerospace, naval sonar, high-speed trains and other fields. As one of the most widely used functional materials, piezoelectric materials are widely used because of their high chemical stability, convenient preparation process, low cost and good piezoelectric properties. Piezoelectric ceramics play an important role in daily life, not only widely used in civil life, but also in military devices. Therefore, the theoretical research on piezoelectric materials is more and more in-depth, and there are also great challenges in piezoelectric measurement. The modal analysis of piezoelectric materials is also the main research direction of piezoelectric materials, and also the main analysis direction to reflect the characteristics of piezoelectric materials. So we need the test data to provide theoretical support. Scanning laser vibration measurement is a perfect method to realize the device modal test. The non-contact laser measurement method and Doppler principle are used to measure the vibration frequency, amplitude, velocity and acceleration, so as to minimize the interference of the external environment and more accurately analyze the vibration mode of the measured object.

A Novel Reciprocating Annular Piezoelectric Actuator: Design, Analysis and Experimental Evaluation

Abstract: In this paper, an annular piezoelectric actuator which can realize reciprocating motion is proposed to provide power for deep-sea bionic system. The actuator adopts a fully open structure, which does not need to consider the problems of sealing and pressure resistance caused by deep-sea pressure. Compared with the DC motor used in traditional underwater propeller, the structure is simpler. At the same time, the actuator is a single-mode actuator with simple control. By using piezoelectric ceramics, the second-order in-plane bending vibration of the stator is excited to drive the rotor to move back and forth along the inner diameter of the stator. A prototype is manufactured and a series of experiments are carried out to reveal its working performance, including the load characteristics of annular piezoelectric actuator, the relationship between swing frequency and driving frequency, and the relationship between swing frequency and voltage. The maximum load of the actuator is 0.2N, the optimal driving frequency is 1235Hz, and the swing frequency is directly proportional to the voltage.

A Sandwich Rotary Traveling Wave Ultrasonic Motor using Wedges for Adjustable Preload:Design and Performance Evaluation

Abstract: In this paper, a sandwich-type rotating traveling wave ultrasonic motor is proposed and investigated. This motor uses the TE vibration mode of piezoelectric ceramics to excite the B(0, 9) working mode of the annular stator to achieve large torque output characteristics. The modal analysis and harmonic response analysis are first conducted using the finite element software, to obtain the optimization geometrical sizes of the motor stator. Then the prototype of the motor is processed and assembled for vibration measurements to confirm the simulation results. Finally, output performance experiments of the motor prototype are carried out to evaluate the motor performances. The results show that the motor prototype can be normally driven by synthesizing traveling waves. Under the driving conditions of 180 N preload, 500Vpp voltage, and 18.4KHz excited frequency, the no-load speed of the motor prototype is 16.64 RPM, and the stall torque is 1Nꞏm. In this paper, a structure design method of the sandwich motor stator is proposed, in which this method can excite two-phase standing waves of the same frequency and orthogonality while ensuring the uniform circumferential stiffness of the motor stator, and can perfectly synthesize traveling waves for driving. Also pioneering the use of wedges to apply adjustable preload to the piezoelectric ceramic sheets.

Research on Optimization of Piezoelectric Composite Cantilever Beam Structure

Abstract: Piezoelectric composite structures have great significance for vibration control and energy harvesting technology. The piezoelectric effect of piezoelectric materials is used to convert mechanical energy into electrical energy based on the positive piezoelectric effect. The positive piezoelectric effect is related to the strain of the structure, which in the relative size and position of the structure affect the energy conversion efficiency. To study the influence of the relative size and relative position of the piezoelectric material and the cantilever beam base on the electric energy capture, a series of analyses, simulations, and experiments were carried out on the piezoelectric cantilever beam. Then, a novel piezoelectric composite structure with the first-order bending vibration was proposed, and the size and proportion of piezoelectric materials were determined. The structural prototype was fabricated, and the measurement system was constructed. The experimental results show that the novel piezoelectric composite structure can improve its electromechanical coupling characteristics, and is suitable for piezoelectric energy harvesting and passive vibration suppression technology.

Bidirectional linear inertial impact piezoelectric motor with multimodal resonance.

Abstract: A new multimodal bidirectional linear inertial impact motor with bidirectional motion based on self-clamping control driven by a single-harmonic signal was designed and manufactured. By applying driving signals of different resonant frequencies to the piezoelectric plate of a piezoelectric motor combined with the unique structural design of the motor, the piezoelectric motor has multiple modes and has the ability of two-way movement. First, the overall structure of the motor is introduced, and its working principle and theoretical displacement characteristics are presented through the periodic motion diagram of the piezoelectric motor. Second, the simulation analysis is carried out to determine the working modal of the proposed motor with COMSOL5.2. Finally, a motor prototype is developed, and the accuracy of the working principle and the simulation analysis is verified through experimental tests. When the motor has no load, the driving voltage is 200 Vp-p. The maximum speed when moving to the right reached 3.125 mm/s when the preload is 2 N, and the driving frequency is 96 Hz. The maximum speed when moving to the left reached 4.301 mm/s when the preload is 4 N, and the driving frequency is 148 Hz. In the load capacity test of the motor prototype, the maximum load of the piezoelectric motor prototype moving to the right and left can reach 0.4 and 0.6 N, respectively. Compared with similar inertial impact motors, the proposed motor achieves flexible control of driving and switching of two-way movement conveniently and has a certain driving ability.

Piezoelectric Micro-Vibration Control of Flexible Arm Driven by Single Motor

Abstract: This work proposed a piezoelectric micro-vibration control method on the flexible arm driven by a stepper motor and a harmonic reducer. In order to introduce the effect of micro-vibration, the dynamic model of the driving mechanism is directly considered in the micro-vibration control system. First, according to the working principle of the stepper motor and the reducer, the theoretical model and the equivalent dynamic model of the stepper motor and the harmonic reducer were derived; then, based on the Lagrange equation modeling method, the entire control system was derived as a nonlinear rigid-flexible and electromechanical coupling dynamics model, which includes the piezoelectric flexible arm, the stepper motor and the harmonic reducer. Furthermore, combined with the proportional velocity negative feedback control algorithm, a micro-vibration closed-loop control model was built using the Simulink platform, and the micro-vibration control effect was simulated and analyzed. The simulation results show that the single drive motor has a significant nonlinear effect on the micro-vibration response of the flexible arm. And the piezoelectric structure has a very effective micro-vibration control effect on the flexible arm driven by a single motor.

Analysis of stator rotor of rotating traveling wave ultrasonic motor

Abstract: As a new type of energy exchange device, the operation characteristics of ultrasonic motor is a hot issue in current research. In this paper, the thermo-electro-mechanical coupling model of the stator and rotor of the rotary traveling wave ultrasonic motor is constructed by finite element software. The frequency and amplitude of the working mode of the stator and rotor of the ultrasonic motor under different temperature conditions are studied, and the influence of the piezoelectric ceramic lamination on the working state of the ultrasonic motor is discussed. The following conclusions are drawn: with the increase of temperature, the resonant frequency of the working mode of the ultrasonic motor B09 decreases and the amplitude increases slightly; piezoelectric ceramic delamination can improve the amplitude-frequency characteristics of stator and rotor. Considering comprehensively, the superposition of two layers of piezoelectric ceramic plates is the most suitable structure.