Single Piezoelectric Plate Research Articles

Applications of Piezoelectricity: Home safety device

The following piezoelectric security doormat is a safety device based on the piezoelectric effect and its converse. Pressure exerted by the person on the doormat is detected by the piezoelectric plates lined inside the mat. These piezoelectric plates are connected in a parallel orientation to make the doormat more durable because if a single piezoelectric plate becomes dysfunctional, the remaining branches will still work and keep the entire system operational. Once the pressure is detected, an electric charge is generated due to the piezoelectric effect. This electric charge is sensed by the Arduino. The coding of the Arduino is done in such a way that whenever it senses an electrical input, the piezo buzzer attached to it is turned on. This piezoelectric buzzer works on the principle of inverse piezoelectric effect where the voltage difference applied induces mechanical stress on the plates producing vibrations. Thus, the security doormat on sensing pressure difference whenever someone stands on it turns on the buzzer connected to it and therefore, alerts the residents.

A Novel, Low-Cost and Reliable Workbench for Optimal Voltage Distribution on Piezoelectric Array Actuators

The vibration control of structures is a valuable technique to increase their integrity and life-cycle. Among smart materials, the passive and active control systems based on piezoelectric elements have been studied in depth. Since the size and location of the piezo-elements on the structure are relevant matters for the damping efficiency, many works have focused on their placement optimization. Under certain circumstances, some structures may be excited by more vibration modes at the same time; hence, the signal conditioning system of the piezoelectric actuators must be capable of adjusting the driving signal in terms of voltage distribution, frequencies and associated amplitudes in order to maximize the damping efficiency. Moreover, in some applications, it could be useful to individually control each actuator therefore tailor-made power supply and signal generation systems are often necessary. This work suggests a low-cost and reliable workbench that overcomes the afore mentioned problems. The system consists of: (1) two arrays of 13 piezoceramic plates which have been glued on an aluminium beam, (2) ad hoc power supply equipment, and (3) mechanical relays arrays managed by a microcontroller for the individual handling of their operating modes. Furthermore, an Arduino board and an in-house software have been implemented in order to perform a task on each relay that is in turn wired to a single piezoelectric plate (PP). The performance of the developed system is evaluated in terms of noise and distortion of the testing signal measured at different points of the workbench. The results show that the proposed workbench may represent a good trade-off between affordability, accuracy and reliability and it can be used for several research purposes.

Enhanced electrical manipulation of magnetic susceptibility in ferromagnetic amorphous alloy and piezoelectric bimorph heterostructure

In this study, we report an enhanced electrical manipulation of magnetic susceptibility in ferromagnetic amorphous alloy ribbon using a piezoelectric bimorph actuator. Theoretically, the strain produced by the piezoelectric bimorph and then coupled into the amorphous alloy ribbon is larger than that of a single piezoelectric plate under an identical applied electric field, thus resulting in a stronger magnetoelectric (ME) coupling for electrically manipulating magnetic susceptibility. Our experimental results have shown that the initial susceptibility tunability of the amorphous alloy ribbon upon the tuning electric field applied on the piezoelectric bimorph ranging from 0 kV/cm to 5 kV/cm can reach up to 750% at low-frequency of 1 kHz and maintain 80% at 1 MHz. This study expands the structure design of ME smart devices, especially the electrically controllable magnetic devices.

A miniature cylindrical piezoelectric motor with an asymmetric vibrator

In this paper, a miniature cylindrical-type traveling wave piezoelectric motor with an asymmetric vibrator is reported. The proposed piezoelectric motor uses only a single piezoelectric plate that is asymmetrically bonded on a cylindrical tube, but it still can excite two bidirectional traveling waves by changing the driving signal frequencies. Typical elliptic motions are observed by using the finite element method (FEM). A prototype motor, whose stator was 8 mm in diameter and 31 mm in length, was fabricated to verify this idea. Our experiments showed that the prototype motor can rotate anticlockwise around the frequency of 21 kHz, at which it works in two degenerated B2 bending coupling modes, and clockwise around 32.7 kHz in two degenerated B22 flexural coupling modes. The results coincide well with our FEM prediction. Finally, further miniaturization was carried out, and a micromotor with 1 mm diameter was constructed, which shows a tunable rotation direction by adjusting the driving signal frequencies. This research has provided a way for piezo-motor miniaturization, with advantages of simple structure and easy driving and control strategy.

Application for generating characteristics of free and bonded systems

AbstractThe present paper is the continuation of earlier publications with stack of piezoelectric plates. This work is an author's idea of application for generating characteristics of piezoelectric systems. The presented program, called Piezo3D, allows for generation a single piezoelectric plate graphs as well as complex, free and bonded systems. An additional advantage is the ability to obtain the 3D graphs, in which the characteristics of the test graph can be based not only on frequency, but also on other parameters such as the thickness of the plate. The application is written in the numerical software "Matlab". (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Computer-Aided Analysis of Piezoelectric Plates

Present paper is a continuation of author’s earlier publications on stacking of piezoelectric plates. Analysis effects are presented by schemes received on the basis of computer calculations. The program is used for creation and analysis of graphical characteristics of piezoelectric plates. The application allows generation of graphs for a single piezoelectric plate as well as for complex systems. An additional advantage is the ability to obtain the 3D graphs, in which the test graph characterizes the plate not only in terms of frequency but can also include other parameters such as the thickness of the plate. The application is written in numerical software "Matlab" in such a way that it is possible to run a program on any computer without the installed software. A necessary condition for the correct operation of the program is availability of “MCR Matlab Compiler Runtime” free library.

Two-dimensional modelling of laminated piezoelectric composites: analysis and numerical results

We propose a new approach to laminated piezoelectric plates based on a refinement of the electric potential as function of the thickness coordinate of the laminate and accounting for shear effects. Moreover, the variation of the electric potential as function of the thickness coordinate is modelled for each layer of the laminate. The equation for the laminated piezoelectric plate are then obtained by using a variational formulation involving mechanical surface loads or prescribed electric potential on the top and bottom faces of the plate. In addition to the equations for the generalized stress resultants (due to the shear effects), the equation of the electric charge conservation is also deduced for the 2D model. Particular attention is devoted to the single piezoelectric plate and bimorph structure and the through-thickness distribution of the displacements, electric potential as well as stresses are given for different kinds of electromechanical loads. The results thus obtained are compared to those provided by a finite element method performed for the full 3D model. A good agreement is observed for plates made of layers of PZT-4 piezoelectric material. The comparison ascertains the effectiveness of the present 2D approach to piezoelectric laminates.

A single plate ultrasonic gyroscope in plane motion

We have proposed a vibration gyroscope made of a single piezoelectric plate in plane motion. The gyroscope makes use of the degenerated modes associated with a square plate. In the present paper, the experimental verification using an enlarged piezoelectric ceramic plate is presented, whose results are compared with the numerical prediction based on two-dimensional and three-dimensional finite element modelling.

Monolithic mosaic transducer utilizing trapped energy modes

A transducer array consisting of a large number of separated sets of electrodes plated on a single piezoelectric plate of uniform thickness is described. Each set of electrodes is made to act essentially independently by placing them sufficiently far apart and employing an essentially trapped energy mode. Experimental results obtained with a linear array on PZT-7A show that the isolation is very good over a bandwidth of about 14%, close to the calculated bandwidth of 12.8%.