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A small disc type piezoelectric motor was developed that can be used for micro flying vehicles. The operating principle of the motor is based on radial-bending type hybrid vibrations. The stator of the motor is a bimorph disc with the special quadrilateral shaped waveguides in the inner circumference of the disc. Waveguides are aligned with the tangential direction of the contacting ring. Such configuration of the actuator allows transforming radial vibrations of the disc into rotational vibrations of the contacting ring. Elliptical motion of the contact points is obtained by superposition of radial and bending vibration modes. The motor has two truncated cone-shaped rotors. Although the actuator is asymmetrical, two coaxial shafts of the motor can be rotated in both directions depending on the phase of excitation signals. Moreover, the proposed piezoelectric motor allows controlling the rotation speed of the rotors in different directions depending on the amplitude of the applied voltage. Numerical and experimental investigation of the piezoelectric motor was performed to validate the operating principle and to analyze vibrations of the contact points. Electrical and mechanical output characteristics of the piezoelectric motor were measured. The motor achieved a maximum no load rotational speed of 7108 rpm at 15 V while maximum torque is 0.0647 mN m.

This paper describes the design, optimization and experimental results of piezoelectric motor that uses the radial mode of excitation of the double rings stator. The main goal of the proposed design is to increase motor performance using d33 ceramic polarization working in the radial mode. The proposed motor can be driven by a simple harmonic signal and used for standard piezoceramic rings. The stator consists of four parts: metal ring, Alumina (Al2O3) ring and double piezoceramic rings. The design is optimized for laser cutting machine and is cost effective for manufacturing. The main application field of the proposed motor is micro-air vehicles (μAV). The finite element method (FEM) was used to define the structural and electrical boundary condition for the symmetrical coplanar trimorph piezoelectric actuator. The results of the numerical calculations after geometry optimization, some experimental results and mechanical properties of the ultrasonic motor are presented in this paper as well.

The paper presents results of numerical and experimental investigations of a new design piezoelectric energy harvester based on a saw-tooth type cantilever array. The proposed energy harvester has multi-modal operation principle and allows to harvest mechanical vibrations energy in narrow frequency range. Moreover, the multi-modal operation principle of the harvester enable summation of bending strains of several cantilevers and allows to improve efficiency of the harvester. The proposed multi-modal energy harvester consist of four cantilevers that are connected rigidly to each other at 30° angles. Cross-sections of the cantilevers were modified by cylindrical gaps in order to increase bending strain. Seismic masses were placed at each corner of the harvester in order to reduce values of natural frequencies and to create additional rotation moment. Numerical investigation revealed that the energy harvester has five resonance frequencies in the range from 20 Hz to 135 Hz. The numerical investigation of electrical characteristics showed that voltage density of 48.39mV/mm3 and energy density of 61.25μJ/mm3 was obtained. Experimental investigations confirmed the results of numerical investigation and showed that voltage and energy densities reached 55.65mV/mm3and 52.56μJ/mm3, respectively.

A plate type standing wave ultrasonic motor which uses built-in galaxy wave transmission mechanism to realize radial-torsional mode conversion is proposed in this paper. Operating principle of the motor is demonstrated, appropriate resonance frequency has been found, and the geometric parameters have been optimized by finite element model analysis. A prototype motor was assembled and a dedicated driver was designed for the purpose of portability, ministration and integration. Dual pulse width modulation (PWM) structure circuit of the driver was designed to achieve the independent control of output voltage amplitude and frequency, which has advantages of control agility and large dynamic adjustment range. Experimental studies were carried out for ultrasonic motor prototype. Maximum no-load speed was measured of 1500 r/min and a maximum output torque of 0.2N $\cdot m$ under the exciting voltage of 150V PP and the frequency of 38.1 kHz. The experimental investigations revealed that the motor has good mechanical output performance under lower driving voltage.

In recent years, with the deepening ocean exploration, autonomous underwater vehicles (AUVs) are in great demand for ocean data collection, marine rescue, underwater communications, environmental monitoring, etc. The miniaturization and clustering of underwater vehicle have become the focus of current research. In order to solve hydraulic and insulation problems of traditional electromagnetic motors, this paper explored the possibility of piezoelectric actuation applied to underwater vehicle and put forward a new type of standing wave ultrasonic motor which was more suitable for miniature underwater vehicle. A disc-type rotary standing wave low driving voltage ultrasonic motor with convex spokes beam was presented. The ultrasonic motor’s work mode was first radial mode. Convex spokes beams were aligned to the tangential direction of the contacting surface of the rotor, which were used to transform radial vibrations of the disc into rotational vibrations of the contacting ring and amplify the axial displacement. The vibration mode of stator was determined by COMSOL finite element method, and verified by Doppler laser vibrator.

A numerical and experimental investigation of a flat, cross-shaped piezoelectric rotary motor is presented. The design and configuration of the motor allow it to be mounted directly to the printed circuit board or integrated into the other system where mounting space is limited. The design of the motor is based on the cross-shaped stator with 16 piezo ceramic plates, which are glued on it. The rotor is placed at the center of the stator and consists of two hemispheres, a shaft, and a preloading spring. Special clamping of the stator was developed as well. It consists of four V-shaped beam structures that allow it to rigidly clamp the stator with reduced damping effect to vibrations. The operation principle of the motor is based on the first in-plane bending mode of the cross-shaped stator. The motor excitation is performed through four harmonic signals, which have a phase difference of π/2. A numerical investigation of the motor was conducted to optimize the geometrical parameters of the stator and to analyze the displacement characteristics of the contacting point. The prototype of the motor was made, and the electrical, as well as rotation speed characteristics of the motor, were measured. The results of the experimental investigation showed that the motor is able to provide a maximum rotation speed of 972.62 RPM at 200 Vp-p when the preload force of 22.65 mN was applied., This article belongs to the Special Issue IWPMA (International Workshop on Piezoelectric Materials and Applications in Actuators) 2019. This paper is an extended version of the paper published in the International Workshop on Piezoelectric Materials and Applications in Actuators in 2019 & Enhance Workshop, IWPMA 2019, held in Lyon, 1–4 October 2019.

A new small size linear type piezoelectric inertia-friction actuator has been developed. The actuator is self-inertia type and operation principle is based on the impact drive. Piezoelectric actuator has simple design and consists of four rectangular bimorph piezoelectric plates fixed in two metal holders that are connected by the two springs. Actuator can operate as self-moving slider on the clamped carbon fiber reinforced plastic rod or it can be clamped to drive the rod. Size of the actuator is 8 × 8.5 × 5.6 mm. Excitation of the actuator can be carried out by single saw tooth or rectangular pulse type signal. Bidirectional motion of the slider is achieved by changing phase of the saw tooth electrical signal by π or duty ratio of the rectangular pulse signal. Numerical investigation of the piezoelectric actuator was performed to analyze natural frequencies, modal shapes and response of the actuator to the different excitation signals. A prototype piezoelectric actuator was made and operating principle of the actuator was validated. Measurements of electrical and mechanical output characteristics were performed. The maximum no load velocity of the slider reaches 40.376 mm/s with driving voltage of 40 V. Actuator achieves maximum thrust force of 0.21 N with the same input voltage.

Energy consumption worldwide is increasing each year. Alternative energy sources supplement these energy demands. Algae are one of such alternative energy sources. As oil needs to be extracted from the ground, algae are needed to be prepared for bio-fuel production. There are a few methods that are used for algae to crack open: chemical and mechanical. Among mechanical methods, the one that is suitable for that purpose is ultrasonication. The current paper presents an ultrasonic cylinder-shape transducer designed for that purpose. Commercial piezo-mechanical systems for algae processing are mostly ordinary longitudinal transducers. The efficiency of such systems is based on irradiation surface, which is normally about 1000 mm 2 . In our system, we propose a different approach to increase the vibration area that produces a cavitation field needed to crack the cell wall of algae. Normally, the active end of transducers is immersed into a reservoir filled with algae-liquid mixture. We propose to create a vibrating reservoir as a part of transducer, thus enlarging the area of acoustic irradiation. Excitation is produced by two full-wave longitudinal transducers orientated opposite to each other and connected to a specifically designed resonant chamber. Experiments have been carried out using two colonial algae species, namely Scenedesmus acutus Meyen and single-cell Monoraphidium griffithii. Comparative experiments have been performed using the standard commercial ultrasonic system for algae processing and the proposed system. The key parameters obtained from the experiments include power consumption and destruction rate.

In this paper, the rotary type ultrasonic motor with bending spokes using radial mode, which can improve the output performance of ultrasonic motor and decrease the cost of manufacture, is presented. The proposed ultrasonic motor has good performance in the output torque and speed. The structure is simple and compact, so it has low dependence on the machining precision. The voltage to drive the motor is low and excitation method is simple. It is suitable for large-scale industrial application also due to its low production cost and reliable output. The current ultrasonic motor is designed for small size flying objects. Moreover, it can be used in miniature helicopter motors and micro-electronic equipment zoom systems such as capsule endoscope, electronic eyeball, SLR camera, smart phone, etc. The proposed motor has a wide application prospect in robot, medical device, micromechanical and aerospace science and technology field. Numerical simulations and experimental outcomes are given. The experimental investigation of the motor has confirmed the main results of numerical analysis and has given an opportunity to create high speed rotation.

One of the most attractive sources of raw materials for biofuel production can be algae oil processing into biofuels. In this paper, the authors are proposing a unique ultrasonic piezoelectric system, which would allow the reduction of internal energy losses and concentration of ultrasonic energy into a small closed volume. The current vibrating systems whose ultrasonic energy is concentrated inside of a hollow cylinder where the water–algae mixture is flowing. The ultrasonic energy is concentrated in a local volume to create a high-power bubble implosion process. Two, three or multiple ultrasonic composite systems to concentrate the total energy into a hollow cylinder in order to create a strong algae cell ultrasonication are used. The experiments and the numerical finite element method (FEM) analysis results using the proposed transducers as well as the biological test results on algae cell disruption by ultra-sonication are presented in this paper.

It is well known that green algae cells are used for bio-fuel production. There are a few known ways of how to process algae cells for oil extraction – chemical and mechanical. Ultrasonic cavitation is one example of mechanical processing that is in use. Longitudinal ultrasonic systems are used for this purpose. In a proposed system the flow of an algae–liquid mixture is created by means of the ultrasonic capillary effect, thus the transducer is the only energy consumer which now acts as a homogenizer (disruptor) and a pump at the same time. What is important is that the capillary is located nearby the strong cavitation field which decreases the chance of unprocessed algae cells flowing into the secondary reservoir. Numerical and comparative tests are done and presented in this paper. The main results are presented in figures and tables, all advantages of the system are outlined in the conclusion section.

Langevin-type piezoelectric transducers are widely used for different industrial applications such as high-accuracy positioning, ultrasonic welding, bonding, drilling, etc. Usually Langevin-type transducers operate at longitudinal mode by employing d33 vibrations of piezoceramic elements. A novel design of piezoelectric actuator based on two bending-type Langevin transducers is introduced. Two half-wavelength transducers are connected by a special aluminum plate. Piezoceramic rings with two-directional polarizations are used for bending oscillation excitation. An input voltage with phase shifted by π/2 on different transducers is applied. The forward and backward elliptical motion of the contact tip is controlled by changing phases of electric signals on different transducers. A numerical simulation was carried out to investigate the trajectories of contact point motion and to validate the operating principle of the actuator. Experimental prototype of the piezoelectric actuator was fabricated, and the measurements of driven tip movements and mechanical output were performed. The results of numerical and experimental analysis are discussed.

A lot of applications are required for surfaces or walls to remain free from airborne particle deposition. A typical example is the deposition of dust on the solar panels in dusty zones. Pollen, bird droppings, dirt, and dust can build up on solar panels. The ultrasonic cleaning action is able to infiltrate the smallest crevices and hard-to-reach surfaces, penetrating areas normally inaccessible to other cleaning methods. During the rarefaction cycle the liquid is torn apart. This creates a vacuum cavity within the liquid. These cavities will grow larger and smaller as the compression waves are continued. This paper proposes a possibility to create the ultrasonic cavity into liquid in motion with depth of water from 0.1 to 1 mm. We are created the ultrasonic cleaning system that performs an ultrasonic cavity in thin water layer in motion ( Fig. 1 ). The finite element method (FEM) was used to define both harmonical analysis and interaction between ultrasonic actuator and medium (air or/and water). The prototype ultrasonic cleaning system was developed and some experimental results were defined. The laser vibrometer used for measuring of mechanical fluctuations on the piezoelectric actuator's surface and measuring results are presented.

An ultrasonic driving principle using friction reduction is proposed and investigated in this paper. In the principle, a continuous ultrasonic push-and-pull driving is combined with a vibration induced friction reduction at desired time intervals, to linearly drive a slider. A linear motor prototype based on this principle is designed, fabricated and measured, and experimental results confirm the proposed principle. The prototype can be driven forwards and backwards, and frequencies of the two voltages for the driving and friction reduction need not to be the same. When the two voltages for the driving and friction reduction are 400 V p–p , the no-load speed and stalling load of the prototype in the forward driving are 187 mm/s and 0.70 N, respectively, and those in the backward driving are 214 mm/s and 0.65 N, respectively.

Investigation of a novel design tiny piezoelectric inertial motor is given in the paper. Operation principle of the motor is based on inertial motion of the slider applying sticks and slip phases between stator and slider. Piezoelectric motor has simple design and consists of the slider with a bimorph piezoceramic disc and the clamped cylindrical shaft used for sliding. The advantage of the motor design is the self-moving slider that obtains bidirectional inertial motion when the saw tooth or the pulse type excitation signal is applied at resonant frequency. Numerical investigation of the piezoelectric motor based on finite elements method was performed to analyse natural frequencies, modal shapes of the motor and slider response to the different excitation regimes. The influence of the Coulomb friction on the velocity of the slider is analysed. A prototype inertial piezoelectric motor was built, and measurements of electrical and mechanical characteristics were performed. The results of numerical and experimental study are discussed.

The earlier “butterfly” type piezomotor (5 × 5 × 6 mm size) developed by authors had a driving force up to 0.5 N. Two identical resonators with a bending-type vibration were joined to one “shaking beam” system for generating an elliptical trajectory of the actuator’s contact point. The researchers at Korean Institute of Science and Technology have improved the contacting elements of the motor and increased the driving force up to 3 N. In the present work, research on increasing the driving force of the motor was continued. The research proceeded in three directions: optimization of the actuator’s eigenmode, optimization of the contacting layer (actuator-driving element) and a determination of the best fixing points of the actuator to the motor’s base. To estimate the characteristics of the current piezomotor, a three-dimensional numerical FEM analysis using ANSYS, was performed. The validity of analysis was confirmed by comparing the experimental results with the numerical ones. As a result of the research, a flat piezoelectrical linear motor with a driving force up to 20 N was fabricated. The mechanical characteristics of the proposed piezomotor are presented in this paper.

A piezoelectric motor capable of omni-directional movements has been developed to apply for robot joints, eyes, and precision positioning stage. The piezoelectric actuator has a simple structure of a cone type consisting of two piezoelectric ring-typed ceramics with electrodes divided into four segments and stainless steel elastic bodies. Before manufacturing the piezoelectric motor, the admittance characteristics and displacements of the actuator as a function of frequency were simulated. Elliptical motions of the actuator were created at several frequencies between the longitudinal and transverse resonance frequencies. The actual motor with alumina ball exhibited nice performance using a driving circuit with two rotary encoders and a PID controller. The moving element was omni-directionally operated at a driving frequency of 53.8 kHz and an output voltage of 280 V(p-p). The developed motor enables the moving element to move to a desired position with a resolution of 1.2 degrees/pulse, an angular velocity of 4 rad/s, and a thrust force of 200 g.

A study of a novel multi-degree-of-freedom piezoelectric actuator is given in the paper. Design of the actuator is based on the implementation of bending vibrations of a circular plate. The actuator consists of a vibrating disc with the driving tip mounted at the disc centre and a piezoceramic disc. This actuator can move a slider in two perpendicular directions in the plane and achieve a curvilinear or rotational motion of the positioned object depending on the excitation scheme of the electrodes. Numerical modelling based on the finite element method was performed to find resonant frequencies and modal shapes of the actuator and to calculate the trajectories of contact point's movements under different excitation schemes. The transient dynamic analysis of the actuator was performed to simulate the motion of the slider. A contact between the driving tip, slider and slider-way was taken into account in the finite element model. A prototype actuator was made and measurement results of actuator's top surface's oscillations are given. Results of the numerical and experimental investigation are analysed and discussed.

In this paper a multi-degree-of-freedom (multi-DOF) ultrasonic motor consisting of a square bar-shaped stator and a spherical or plate type rotor was developed. It can generate multi-DOF rotation of the rotor using “shaking beam” principle of linear motion formation based on previous researches. The multi-DOF rotation generated by four contacting points of a square bar-shaped actuator using four d31 piezoelectric plates. The computer simulation by finite element analysis of proposed system is given. The authors used precision laser equipment for testing and measuring both contacting points and surfaces of square bar-shaped actuator.

A study of a novel design composite piezoelectric actuator for omnidirectional object positioning is given in the paper. The actuator consists of a vibrating disc with a small cylinder mounted at the centre and a piezoceramic disc. The cylinder magnifies resonant bending vibrations of the vibrating disc and transmits driving force to the slider. Electrodes of the piezoceramic disc cover all the surface of the bottom and are divided into four equal sectors. 2D motion and rotation of the slider is achieved depending on the excitation scheme of the electrodes. Numerical modeling based on the finite element method was performed to obtain resonance frequencies and modal shapes of the actuator and to calculate the trajectories of contact point’s movements under different excitation schemes of the electrodes. A prototype actuator was made and experimental outcomes of the oscillations of the working surfaces are given. Results of the numerical and experimental investigations are analyzed and discussed.

Several positioning tasks demand translatory drive instead of rotary motion. To achieve drives that are capable, e.g., to drive the sunroof of a car or to lift a car’s window, multiple miniaturized motors can be combined. But in this case many other questions arise: The electromechanical behavior of the individual motors differs slightly, the motor characteristics are strongly dependent on the driving parameters and the driven load, many applications need some extra power for special cases like overcoming higher forces periodically. Thus, the bundle of motors has to act well-organized and at last controlled to get an optimized drive that is not oversized and costly.

Classically, rotary motors with gears and spindle mechanisms are used to achieve translatory motion. In means of miniaturization and weight reduction piezoelectric linear motors are of interest. Several ultrasonic linear motors found in literature base on the use of two different vibration modes. Most often flexural and longitudinal modes are combined to achieve an elliptic micro-motion of surface points. This micro-motion is converted to direct linear (or translatory) motion of a driven slider. To gain high amplitudes of the micro-motion and thus having a powerful motor, the ultrasonic vibrator should be driven near the eigenfrequency of its modes. Additionally, low mechanical and electrical losses lead to increased efficiency and large amplitude magnification in resonance. This demands a geometrical design that fits the eigenfrequencies of the two different modes. A frequency-deviation of only a few percent leads to non-acceptable disturbance of the elliptical motion. Thus, the mechanical design of the vibrators has to be done very carefully. Within this contribution we discuss different motor designs based on the coupling of two the same longitudinal vibrations within one structure to generate an elliptic motion of surface points. Different concepts based on piezoelectric plates and Langevin transducers are compared. Benefits and drawbacks against the combination of longitudinal and bending modes will be discussed. Numerical results of the stator vibration as well as motor characteristics are validated by measurements on different prototypes.

According to previous research on the creation of linear piezo-motors using the “shaking beam” principle the authors have proposed a new rotating type piezo-motor based on the same principle. The advantage of the current motor compared with analogues motors is shown. The proposed motor uses both actuator of longitudinal-torsion vibration and a wave motor. In this paper computer simulation by FEM analysis of the proposed system is given. The simulation results of modeling are confirmed experimentally. The authors used precision laser equipment for testing and measuring.

Rotary ultrasonic motors have found broad industrial application in camera lens drives and other systems. Linear ultrasonic motors in contrast have only found limited applications. The main reason for the limited range of application of these very attractive devices seems to be their small force and power range. Attempts to build linear ultrasonic motors for high forces and high power applications have not been truly successful yet. To achieve drives, larger force and higher power, and multiple miniaturized motors can be combined. This approach, however, is not as simple as it appears at first glance. The electromechanical behavior of individual motors differs slightly due to manufacturing and assembly tolerances. Individual motor characteristics are strongly dependent on the driving parameters (frequency, voltage, temperature, pre-stress, etc.) and the driven load and the collective behavior of the swarm of motors is not just the linear superposition of the individual drive’s forces.

Investigation of a new design piezoelectric actuator based on research of compound ultrasonic systems called shaking beam is presented in the paper. It was developed to rotate the sphere about three different axes and can be used in sophisticated positioning devices. The actuator consists of a vibrating frame, four piezostacks and four overlays. Elliptical motions of the four driving tips, which rotate the sphere, are achieved by using multimode oscillations of the vibrating frame. Control of the sphere's motion is performed by managing the amplitude and phase of harmonic input signal on different piezostacks. Numerical modeling based on a finite element method is performed in order to obtain resonance frequencies and modal shapes of the actuator and to calculate the trajectories of contact points movements under different input regimes. A prototype actuator was made and the experimental outcomes of the actuator's working surfaces oscillations are given. Results of the numerical and experimental research are analyzed and discussed.

The new-typed tiny ultrasonic motor has been introduced to have compact and simple structure. The linear motion of a new-type linear motor is operated by a principle of inertia displacement. The motor can be realized by the central movement of transducing part, which is the maximum displacement of the up-and-down movement. The transducing parts, using different diameters, 3.0 and 5.0 mm and thickness of 0.1 and 0.2 mm metal disks, were fabricated and the dynamic characteristics of the motors were measured. The motor with piezoelectric ceramic of O3 needs higher operating voltage than the motor with the piezoelectric ceramic of O5.

In present work, the analysis of moving of positioning table in a plane is indicated. For this purpose, only one piezoelectric motor without intermediate parts is created. Being based on researches of compound ultrasonic piezoelectric systems called “shaking beam” is developed actuator for moving of a body in a plane at any direction. Computer modeling of the actuator is carried out. The prototype is made. The experimental outcomes of the oscillation forms of working surfaces of an actuator are given.

In this paper, piezoelectric linear ultrasonic motors (PLUM) have been investigated on the elliptic trajectory of a contact point in shaking beam, which has been accomplished by two resonance vibration modes of the actuators. The actuators have generated the vibration modes, longitudinal and flexural, by two longitudinal mechanical vibrations with phase difference of /spl pi//2. Modal and harmonic analysis of the shaking beam actuator were performed by the finite element method (FEM) to calculate a resonance frequency and a modal shape and to perform harmonic response. Experimental results proved that a contact point of the PLUM tends to move with an elliptic trajectory.

In this paper the ultrasonic linear motor based on shaking beam and nano-positioning mechanical system were investigated. The advantages of the ultrasonic linear motor are high resolution, no magnetic noise generation due to the DC characteristics of the piezoelectric device, high servo rigidity, high holding torque and none additional brake system. It was confirmed that ultrasonic linear motor is suitable for nano-motion positioning with various speeds at close-loop control. The ultrasonic linear motor based on shaking beam was described and the nano-positioning systems using the ultrasonic linear motor were investigated.

Nowadays for algae cell ultrasonication the longitudinal ultrasonic piezosystems are used. In this paper a possibility of creating unique ultrasonic piezoelectric system, which would allow reducing energy losses and concentrating this energy to a small closed volume are proposed. The current vibrating systems whose ultrasonic energy is concentrated inside of hollow cylinder in which water-algae mixture is flowing. Two, three or multiply ultrasonic composite systems to concentrate total energy into a hollow cylinder to creating strong algae cell ultrasonication are used. The experiments and numerical FEM analysis results using diskshaped transducer and the first biological test results on algae cell disruption by ultrasonication are presented as well., {"references":["Peshkovsky S., Peshkovsky A. Matching a transducer to water at\ncavitation - acoustic horn design principles. UltrasonicsSonochemistry,\nVol. 14, Issue 3, 2007, p. 314-322.","Peshkovsky S., Peshkovsky A. Ultrasonic rod waveguide-radiator.\nUnites States patent No. US 7156201 B2.","Peshkovsky S., Peshkovsky A. High capacity ultrasonic reactor system.\nUnites States patent No. US 2010/0296975 A1.","P. P. Prohorenko, N. V. Dezhkunov and G. E. Konovalov, Ultrasonic\ncapillary effect. Science and Technology, 1981, 135 p.","VioletaMakarevičienė V., Andrulevičiūtė V., VirginijaSkorupskaitė V.,\nKasperovi─ìien─ù J. Cultivation of Microalgae Chlorella sp. and\nScenedesmus sp.as a Potentional Biofuel Feedstock. Aplinkostyrimai,\ninžinerijairvadyba, Nr. 3(57), 2011, p. 21 - 27.","Sieg D. Making Algae Biodiesel at Home. 2009.","http://www.hielscher.com/ultrasonics/i1000_p.htm","http://sonomechanics.com/technology/ultrasonic_horn_designs_and_pro\nperties/"]}

Automatic systems are widely integrated at dangerous application fields under unsafe environment for safety reason or to change the monotonous human work by robotic systems. Modern standards are rising higher for modern equipment so the maintenance of such equipment must be at the same level. In this paper the ultrasonic cleaning system for sloping surfaces is proposed. Current system is self turning and rain-triggered and can be perfectly used for solar panels or roof windows cleaning. The ultrasonic wave imparts directly on a film of fluid no more than a few millimeters thick on the surface. The proposed system has low power consumption and does not require any maintenance itself. The prototype of proposed system is developed in our laboratory.

High power Langevin piezoelectric transducers have large dielectric and piezoelectric losses. Most of these losses are converted into accumulating internal heat that increases the temperature of the transducer. In this paper we analyze how to minimize heat generation and reduce temperature of the transducer. The modification of transducer design is proposed by separating piezoceramic elements and adding a metal block between the elements. Analytical and numerical modeling of the Langevin transducer was carried out to find the dependence of the oscillation amplitudes and temperatures on the location of the separated piezoceramic elements and thermal properties of the additional metal part. Two prototypes of the Langevin transducer with two different locations of the piezoceramic elements were fabricated. Measurements of the vibration amplitudes of the contact point and temperature distribution along the transducers were done. Measurement results are compared with the numerical results.

Study of a novel design miniature linear piezoelectric motor is proposed in the paper. Size of the motor not exceeds 150 mm3. Piezoelectric motor consists of “butterfly” type actuator and slider. Elliptical trajectory of the actuator is achieved using bending oscillations of the plates of actuator when harmonic or short impulse type excitation is used. Contact zone trajectory of motion is analyzed for both type of excitation. Advantages of impulse type excitation are simpler electric circuit scheme, lesser dependence between the rotor torque and excitation frequency. It allows increasing torque of the rotor without increasing dimensions and mass of the actuator. Numerical modeling of the piezoelectric motor was done to analyze natural frequencies, modal shapes of the actuator and to examine actuator response to the harmonic and impulse type excitation. Experimental prototype of the piezoelectric motor was built and measurement contact zone motion was done. Results of numerical and experimental studies are discussed.

The present invention relates to a linear motor which draws its operating power from ultrasonic vibration above the frequency of 20 kHz which is generated by piezoelectric ceramic. More particularly, the invention relates to a linear piezoelectric ultrasonic motor which linearly operates a slider due to a frictional force generated by applying sinusoidal electric field with a 90 degree phase difference to a pair of piezoelectric ceramic. This causes an elliptical mechanical vibration on a shaking beam which is connected to the piezoelectric ceramic.

The transformation of high-frequency vibrations of piezoelectric elements into continuous linear motion of a slider is one of the main tasks of a linear piezoelectric motor. To produce a high thrust force in the piezoelectric linear actuator, we proposed the compound piezoelectric linear actuator based on a “shaking beam” excited by two sources of longitudinal mechanical vibrations shifted by π/2. The compound actuator consists of two shaking beams and is rigidly fastened. The finite element method (FEM) was used to define structural and electrical boundary conditions for the compound piezoelectric actuator. FEM analysis showed that the compound actuator's trajectory was elliptical. Experimental research has shown that the compound piezoelectric actuator has high thrust force.

A new ultrasonic actuator based on a bending-type Langevin piezoelectric transducer has been developed. An actuator consists of a half-wavelength Langevin transducer and an aluminum plate that is mounted in the middle of the transducer. The driving tip is located at the bottom of the aluminum plate. Piezoceramic rings with opposite polarity within each half of the ring are divided into two groups. Two harmonic signals with shifted phases by π/2 are used to excite the first bending mode of the Langevin transducer and aluminum plate. Elliptical trajectory of the contact point motion is obtained by combining these two bending modes. Numerical modelling was carried out to analyze harmonic response of the actuator and to investigate the trajectories of the contact point motion. Optimization of the aluminum plate design was performed to maximize the parameters of elliptical motion of the driving tip. A prototype actuator was fabricated, and output characteristics were measured. The results of numerical and experimental study are discussed.

Piezoelectric actuators are widely used for different applications such as high precision positioning devices, micromanipulation systems, scanning microscopes, and robotic systems. This paper introduces a compact size symmetrical coplanar trimorph piezoelectric actuator for high speed (up to 5000 rpm) rotary motors. The actuator consists of a hollow carbon cylinder and a disc-type coplanar piezoelectric trimorph actuator. The cylinder is glued in the center of the trimorph disc. The electrodes of the piezoelectric layers of the actuator are divided into the four equal sections. Four electric signals with shifted phases by π/2 are applied on the different electrodes, and traveling wave oscillations of the disc and rotational motion of the cylinder are excited. Numerical modelling based on the finite element method was performed to find the resonant frequencies and modal shapes of the actuator and to calculate the trajectories of contact point movements. The optimization of the actuator design has been performed to maximize the oscillation amplitude of the contact point. A prototype actuator was then made, and measurement of the actuator's resonant frequency and rotational speed has been performed. The results of the numerical and experimental investigation are analysed and discussed.

Several positioning tasks demand translatory drive instead of rotary motion. To achieve drives that are capable e.g. to drive the sunroof of a car or to lift a car's window, multiple miniaturized motors can be combined. But in this case many other questions arise: the electromechanical behavior of the individual motors differs slightly, the motor characteristics are strongly dependent on the driving parameters and the driven load, many applications need some extra power for special cases like overcoming higher forces periodically. Thus, the bundle of motors has to act well organized and controlled to get an optimized drive that is not oversized and costly.

Biofuel production from algae oil is one of the most attractive process technologies. Few principles of algae cell disruption are presented on the market and introduced on the conference. Mainly, mechanical, thermal and ultra-sonication technologies are widely used in biofuel production. In this paper, authors propose a novel method for algae cell disruption – electrohydraulic shock in the water (Yutkin effect). The short-term plasma can be determined as an effective method for algae cell wall disruption. The experimental results using the proposed method as well as the biological test performed using Scenedesmus algae specie are presented

Development of multi degree-of-freedom (DOF) high-resolution motors is becoming of increased importance for nanotechnology, micro-robotics, and laser technology. A novel design of 3DOF rotary type piezoelectric motor is proposed. It includes three novel 2DOF inertial piezoelectric actuators, housing, and hemispherical rotor. 2DOF actuator consists of a piezoelectric bimorph disc with the quadrilateral shaped waveguides in the inner circumference of the disc and carbon fiber rod. Such configuration of the bimorph disc is used to transform radial vibrations of the disc into rotational oscillations of the rod. The piezoelectric actuator operates in two vibration modes, i.e., the first out-of-plane bending mode of the disc at 20.5 kHz and the first radial mode of the disc at 138.2 kHz. The bending mode is used to rotate the rotor about x and y axes, while the radial mode is used to obtain rotation about the z-axis. Each piezoelectric actuator is supplied with sawtooth or square waveform voltage, therefore the rotor is driven based on friction – inertia principle. Numerical and experimental investigation of the piezoelectric motor was performed, and results are discussed.