scholarly journals Generation of Linear Traveling Waves in Piezoelectric Plates in Air and Liquid

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 283 ◽  
Author(s):  
Alex Díaz-Molina ◽  
Víctor Ruiz-Díez ◽  
Jorge Hernando-García ◽  
Abdallah Ababneh ◽  
Helmut Seidel ◽  
...  

A micro- to milli-sized linear traveling wave (TW) actuator fabricated with microelectromechanical systems (MEMS) technology is demonstrated. The device is a silicon cantilever actuated by piezoelectric aluminum nitride. Specifically designed top electrodes allow the generation of TWs at different frequencies, in air and liquid, by combining two neighboring resonant modes. This approach was supported by analytical calculations, and different TWs were measured on the same plate by laser Doppler vibrometry. Numerical simulations were also carried out and compared with the measurements in air, validating the wave features. A standing wave ratio as low as 1.45 was achieved in air, with a phase velocity of 652 m/s and a peak horizontal velocity on the device surface of 124 μm/s for a driving signal of 1 V at 921.9 kHz. The results show the potential of this kind of actuator for locomotion applications in contact with surfaces or under immersion in liquid.

Author(s):  
Yu-Hsiang Hsu ◽  
Tsung-Yu Chu ◽  
Zi-Xun Lin ◽  
Chih-Kung Lee

Abstract In this study, we present a new driving method to generate traveling waves in a finite plate for the application of piezoelectric motorizations. Due to resonant modes which dominate the vibration of finite structures, methods to reduce resonant effects such as using an electric sinker or driving at a non-resonant frequency, have been reported. To take the advantage of natural resonance and to increase driving efficiency, a new method entitled a gated two-frequency-two-mode (G-TFTM) was developed. A piezoelectric bimorph of 1.1g weight with two rectangular actuators was implemented to verify the design concept. One actuator was operated at a first bending mode and the other actuator operated at a second bending mode with phase difference. The driving signal was gated to generate an intermittent excitation to provide a periodic propulsion. To determine the profile of the induced traveling wave, an analytical solution was derived and a numerical model was used. Using these design tools, we experimentally verified that traveling waves can be generated using a G-TFTM method. A 0.1 g object can be moved at a speed of 3.31 mm/s under the condition of a 70-to-20 voltage ratio and a 137-degree phase difference. The moving direction was found to be reversed by changing the phase to -43 degrees. The experimental and numerical data are detailed in this paper to demonstrate the feasibility of this G-TFTM method.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mostafa M. A. Khater ◽  
Choonkil Park ◽  
Jung Rye Lee ◽  
Mohamed S. Mohamed ◽  
Raghda A. M. Attia

AbstractThe accuracy of analytical obtained solutions of the fractional nonlinear space–time telegraph equation that has been constructed in (Hamed and Khater in J. Math., 2020) is checked through five recent semi-analytical and numerical techniques. Adomian decomposition (AD), El Kalla (EK), cubic B-spline (CBS), extended cubic B-spline (ECBS), and exponential cubic B-spline (ExCBS) schemes are used to explain the matching between analytical and approximate solutions, which shows the accuracy of constructed traveling wave solutions. In 1880, Oliver Heaviside derived the considered model to describe the cutting-edge or voltage of an electrified transmission. The matching between solutions has been explained by plotting them in some different sketches.


2014 ◽  
Vol 960-961 ◽  
pp. 1100-1103
Author(s):  
Guang Bin Zhang ◽  
Hong Chun Shu ◽  
Ji Lai Yu

Wavefront identification is important for traveling based fault location. In order to improve its reliability, a novel wavefront identification method based on Harris corner detector has been proposed in this paper. The principle of single-ended traveling wave fault location was briefly introduced at first, and the features of wavefronts generated by faults on transmission lines were analyzed. The arrival of traveling waves' wavefronts is considered as corner points in digital image of waveshape. The corner points can be extracted precisely by Harris corner detector, and both false corner points and non-fault caused disturbance can be eliminated according to the calculated distance between two neighbour corner points and the angle of the corner point. The proposed method is proved feasible and effective by digital simulated test.


Author(s):  
J-B Li ◽  
K Jiang ◽  
G J Davies

A novel die-sinking micro-electro discharge machining (EDM) process is presented for volume fabrication of metallic microcomponents. In the process, a high-precision silicon electrode is fabricated using deep reactive ion etching (DRIE) process of microelectromechanical systems (MEMS) technology and then coated with a thin layer of copper to increase the conductivity. The metalized Si electrode is used in the EDM process to manufacture metallic microcomponents by imprinting the electrode onto a flat metallic surface. The two main advantages of this process are that it enables the fabrication of metallic microdevices and reduces manufacturing cost and time. The development of the new EDM process is described. A silicon component was produced using the Surface Technology Systems plasma etcher and the DRIE process. Such components can be manufactured with a precision in nanometres. The minimum feature of the component is 50 μm. In the experiments, the Si component was coated with copper and then used as the electrode on an EDM machine of 1 μm resolution. In the manufacturing process, 130 V and 0.2 A currents were used for a period of 5 min. The SEM images of the resulting device show clear etched areas, and the electric discharge wave chart indicates a good fabrication condition. The experimental results have been analysed and the new micro-EDM process is found to be able to fabricate 25 μm features.


Author(s):  
Noah H. Schiller ◽  
Sz-Chin Steven Lin ◽  
Randolph H. Cabell ◽  
Tony Jun Huang

This paper describes the design of a thin plate whose thickness is tailored in order to focus bending waves to a desired location on the plate. Focusing is achieved by smoothly varying the thickness of the plate to create a type of lens, which focuses structure-borne energy. Damping treatment can then be positioned at the focal point to efficiently dissipate energy with a minimum amount of treatment. Numerical simulations of both bounded and unbounded plates show that the design is effective over a broad frequency range, focusing traveling waves to the same region of the plate regardless of frequency. This paper also quantifies the additional energy dissipated by local damping treatment installed on a variable thickness plate relative to a uniform plate.


2008 ◽  
Vol 18 (01) ◽  
pp. 219-225 ◽  
Author(s):  
DANIEL TURZÍK ◽  
MIROSLAVA DUBCOVÁ

We determine the essential spectrum of certain types of linear operators which arise in the study of the stability of steady state or traveling wave solutions in coupled map lattices. The basic tool is the Gelfand transformation which enables us to determine the essential spectrum completely.


2005 ◽  
Vol 16 (05) ◽  
pp. 815-826 ◽  
Author(s):  
HONGBIN ZHANG ◽  
CHUNGUANG LI ◽  
GUANRONG CHEN ◽  
XING GAO

Recently, a new hyperchaos generator, obtained by controlling a three-dimensional autonomous chaotic system — Chen's system — with a periodic driving signal, has been found. In this letter, we formulate and study the hyperchaotic behaviors in the corresponding fractional-order hyperchaotic Chen's system. Through numerical simulations, we found that hyperchaos exists in the fractional-order hyperchaotic Chen's system with order less than 4. The lowest order we found to have hyperchaos in this system is 3.4. Finally, we study the synchronization problem of two fractional-order hyperchaotic Chen's systems.


2001 ◽  
Author(s):  
Emily J. Pryputniewicz ◽  
John P. Angelosanto ◽  
Gordon C. Brown ◽  
Cosme Furlong ◽  
Ryszard J. Pryputniewicz

Abstract Using recent advances in microelectromechanical systems (MEMS) technology, a new multivariable sensor was developed. This MEMS sensor, capable of measuring temperature, absolute pressure, and differential pressure on a single chip, is particularly suitable for applications in process control industry. However, functional operation of the sensor depends on validation of its performance under specific test conditions. We have developed a hybrid methodology, based on analysis and measurements, that allows such validation. In this paper, the MEMS multivariable sensor is described, the hybrid methodology is outlined, and its use is illustrated with representative results.


2012 ◽  
Vol 81 ◽  
pp. 65-74 ◽  
Author(s):  
Jacopo Iannacci ◽  
Giuseppe Resta ◽  
Paola Farinelli ◽  
Roberto Sorrentino

MEMS (MicroElectroMechanical-Systems) technology applied to the field of Radio Frequency systems (i.e. RF-MEMS) has emerged in the last 10-15 years as a valuable and viable solution to manufacture low-cost and very high-performance passive components, like variable capacitors, inductors and micro-relays, as well as complex networks, like tunable filters, reconfigurable impedance matching networks and phase shifters, and so on. The availability of such components and their integration within RF systems (e.g. radio transceivers, radars, satellites, etc.) enables boosting the characteristics and performance of telecommunication systems, addressing for instance a significant increase of their reconfigurability. The benefits resulting from the employment of RF-MEMS technology are paramount, being some of them the reduction of hardware redundancy and power consumption, along with the operability of the same RF system according to multiple standards. After framing more in detail the whole context of RF MEMS technology, this paper will provide a brief introduction on a typical RF-MEMS technology platform. Subsequently, some relevant examples of lumped RF MEMS passive elements and complex reconfigurable networks will be reported along with their measured RF performance and characteristics.


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