Piezoelectric Cymbal Transducer Research Articles

Design and Analysis of Two Piezoelectric Cymbal Transducers with Metal Ring and Add Mass.

Based on traditional sandwich structure, two piezoelectric transducers were designed to meet the strict underwater application backgrounds such as high pressure, corrosion resistance, and high strength. Both transducers integrated most of previous researches while one transducer has a multilayer cavity structure which is different from the other structure and previous transducer structures. After a detailed simulation analysis of every structural parameter, key parameters were pointed out to have an obvious influence on its performance. Then, two models were constructed and compared with chosen sets of geometry parameters and manufacturing process, which can also provide a reference for low-frequency transducer design. The simulation results and experimental results of our transducers show a good consistency which indicates the cavity structure can reduce the resonance frequency.

Development of a Novel Compression-Based Piezoelectric Traffic Model for Improving the Roadways Energy Harvesting System by Applying the Celular Atomata Traffic Model

- The purpose of this paper is to conduct simulations to increase and analyse the harvested energy in roadway applications. An electromechanical-traffic model of compression-based piezoelectric energy harvesting that exploits the vibrations derived from traffic movement is also simulated as well as being studied on the critical system parameters (e.g. behaviour of traffic flow, number of vehicles, the optimum electrical load, the maximum voltage and the area) accurately based on the simulation of data. Therefore, these factors are considered when designing the traffic model to produce the optimal power. The most significant outcome of this research is the harvesting of electrical energy from piezoelectric arrays by using roadway applications to generate various scales of useable power. The focus from vehicles are on testing and simulating one set array of Piezoelectric Cymbal Transducer (PCTs) and two set arrays of PCTs. By proposing an electromechanical-traffic model of compression-based piezoelectric energy harvesting, simulating it under different parameters include mean arrival rate (I»), resistance, single lane, two lanes, single PCT and arrays of PCTs. Besides, the Cellular Automata (CA) traffic model is used to represent the traffic flow model. On average, the obtained results show that the highest total power is generated at the highest arrival rate and low resistance The generated power for a single lane with 2 arrays of PCTs is as much as 170W and 345W for two lanes with two arrays of PCTs. The results also show that at low resistance the output power increases whenever the number of PCTs and lanes increase.

Optimization of the Compression-Based Piezoelectric Traffic Model (CPTM) for Road Energy Harvesting Application

This paper employs the Two-Degree-of-Freedom (2DOF) electromechanical model to show the probability of the piezoelectric approach as an option for energy scavenging devices in roadway applications. The passing vehicles are the main energy source for harvesting device. A 2DOF electromechanical model as the piezoelectric harvesting unit is applied to explain the harvester performance in a single lane road. APC piezoelectric ceramic (APC 855) is selected as the optimum piezoelectric material due to its high piezoelectric constant values and high piezoelectric charge constant. Also, in the traffic model, we employ a Cellular Automata (CA) model. The vehicle dynamics model is used to transfer information from the traffic model to the piezoelectric model. Combining both the traffic model, i.e. the piezoelectric and the vehicle dynamics model, results in the compression-based piezoelectric traffic model (CPTM). In a single-lane traffic model with different arrival rate I», a single circle-shaped Piezoelectric Cymbal Transducer (PCT) with thickness of 0.3 mm and diameter of 32 mm is applied, in which the produced power is 14.126 W and 29.746 W and 6.47 W. Based on these outcomes, if we lay multiple PCT arrays along the highway road, a large amount of power can be produced. Hence, a great potential is shown by the proposed electromechanical-traffic model for applications related to the macro-scale roadway electric power generation systems.

The design and analysis for low-frequency piezoelectric cymbal transducers

Abstract Piezoelectric cymbal transducers (PCT) have been widely used in energy harvesting. Previous researches recommend PCTs with symmetric geometry to avoid the disadvantages, such as failure of the epoxy layers due to the high frequency loads. In the current study, the applicability of the asymmetric cymbal transducer for low frequency is evaluated by finite element method. Three types of transducers are compared, including Type I, which is the conventional transducer, Type II with the apexes of the top and bottom cymbals shifted in the same directions, and Type III with the apexes shifted in the opposite direction. The results show that the optimized Type II and III transducers improve power output by 7.1% and 15.9%, respectively, compared with Type I. Moreover, a numerical method is proposed to decompose the strain states of the piezoelectric disc into the superposition of sets of the strain state basis of the radial resonance modal shapes. The results reveal the relationship between the resonant modal shapes and the increase of the power output. A new design of PCT is proposed. The current work provides design guideline for the application to energy harvesting systems which is particularly suitable for traffic-induced vibrations.

Electromechanical-Traffic Model of Compression-Based Piezoelectric Energy Harvesting

Piezoelectric energy harvesting has advantages over other alternative sources due to its large power density, ease of applications, and capability to be fabricated at different scales: macro, micro, and nano. This paper presents an electromechanical-traffic model for roadway compression-based piezoelectric energy harvesting system. A two-degree-of-freedom (2-DOF) electromechanical model has been developed for the piezoelectric energy harvesting unit to define its performance in power generation under a number of external excitations on road surface. Lead Zirconate Titanate (PZT-5H) is selected as the piezoelectric material to be used in this paper due to its high Piezoelectric Charge Constant (d) and Piezoelectric Voltage Constant (g) values. The main source of vibration energy that has been considered in this paper is the moving vehicle on the road. The effect of various frequencies on possible generated power caused by different vibration characteristics of moving vehicle has been studied. A single unit of circle-shape Piezoelectric Cymbal Transducer (PCT) with diameter of 32 mm and thickness of 0.3 mm be able to generate about 0.12 mW and 13 mW of electric power under 4 Hz and 20 Hz of excitation, respectively. The estimated power to be generated for multiple arrays of PCT is approximately 150 kW/ km. Thus, the developed electromechanical-traffic model has enormous potential to be used in estimating the macro scale of roadway power generation system.

Floor Tile Energy Harvester for Self-Powered Wireless Occupancy Sensing

Abstract We investigate a concept that can reduce the overall power requirement of a smart building through improvements in the real-time control of HVAC and indoor lighting based on the building occupancy. The increased number of embedded sensors necessary to realize the smart building concept results in a complex wiring and power structure. We demonstrate a floor tile energy harvester for creating a wireless and self-powered occupancy sensor. This sensor termed as “Smart Tile Energy Production Technology (STEP Tech)” can be used to control automation in smart buildings such as lighting and climate control based upon the real-time building occupancy mapping. The sensor comprises of piezoelectric transducer, energy harvesting circuit and wireless communication. Modeling and optimization procedure for the piezoelectric cymbal transducer is described within the framework of tiles. The design and selection of a packaging technique and construction of a durable floor tile enclosure aimed at protecting the bulk piezoceramic is discussed within the constraint that the deflection of the tile should be minimal such that it is not readily perceivable by humans, thus not disturbing their gait. Experimental results demonstrate that the piezoelectric tile could provide a promising solution for wireless occupancy sensing.

Study of Energy Harvesting Using Piezoelectric Cymbal Transducers

The performance of harvesting energy using piezoelectric cymbal transducers has been studied from gentle mechanical vibration under different pre-stress conditions. The cymbal transducer was fixed at 12.9 mm diameter and evaluated the output power of harvesting energy under an AC force of 0.7 N. The maximum power output reached 3.7mW with a slight stress level of 0.17 N across 50 kohm resistor for the cymbal transducer at the 730 Hz. The resonance frequency of the cymbal was shifted to lower value and the harvesting energy was increased with the pre-stress increased. The analytical results were found to be in good agreement with the experimental results. It is suggested that great potential for cymbal transducers exists in energy harvesting applications.

Giant magnetoelectric effect in magnet-cymbal-solenoid current-to-voltage conversion device

A giant magnetoelectric (ME) effect is reported in a current-to-voltage (I-to-V) conversion device formed by sandwiching a PZT piezoelectric cymbal transducer between an NdFeB magnet and a Fe-core solenoid. The observed ME effect results from the direct coupling of the electromagnetically induced attractive-repellent force effect in the magnet-solenoid assembly with the amplified piezoelectric effect in the cymbal transducer. The device exhibits a colossal I-to-V conversion factor (S) of 27.1 V/A with a giant ME coefficient (αV) of 1.24 V/Oe at a low resonance frequency of 2.33 kHz, besides a large S of 0.74 V/A with a high αV of 34 mV/Oe in the nonresonance frequency range of 40 Hz–1 kHz. A physical model based on the combination of electromagnetomechanics in the magnet-solenoid assembly and amplified piezoelectricity in the cymbal transducer is present to explain the observed ME effect and the resulting I-to-V conversion in the device.