Piezoelectric Micro-generator Characterization for Energy Harvesting Application Jos´ e E. Q. Souza, Marcio Fontana, Antonio C. C. Lima Abstract—This paper presents analysis and characterization of a piezoelectric micro-generator for energy harvesting application. A low-cost experimental prototype was designed to operate as piezoelectric micro-generator in the laboratory. An input acceleration of 9.8m/s 2 using a sine signal (peak-to-peak voltage: 1V, offset voltage: 0V) at frequencies ranging from 10Hz to 160Hz generated a maximum average power of 432.4μW (linear mass position = 25mm) and an average power of 543.3μW (angular mass position = 35°). These promising results show that the prototype can be considered for low consumption load application as an energy harvesting micro-generator. Keywords—Piezoelectric, microgenerator, energy harvesting, cantilever beam. I. I NTRODUCTION N OWADAYS, most sensors that use wireless technologies are still powered by someone traditional sources of power or batteries. However, the advance electronic technologies and alternative power demand for wireless sensors supply make energy harvesting an attractive and feasible solution [1], [2]. Vibration is one of the mechanical phenomenon that has a great potential for energy harvesting. This phenomenon, combined with the monitoring of industrial equipments for predictive maintenance, introduce novel area of wireless sensors technologies. Electrical machines and electrical generators are typical equipment used in minihydro, micro-turbines fueled by natural gas or landfill gas, and wind turbines because of their low-inertias. The fundamental mechanical vibration of these machines is 50Hz/60Hz (3000RPM/3600RPM for 2-pole machines). However, the dominant mechanical frequency is below the 30Hz range. These vibration frequencies are associated to the horizontal movement and the vertical motion of equipments [3]–[5]. These low frequencies can be used like excitation source of piezoelectric micro-generators for energy harvesting application. There are currently three basic types of transducers capable of generating energy from vibration: electromagnetic [6], electrostatic [7] and piezoelectric [8], [9]. Although electromagnetic and electrostatic generators have a high generation capacity. These transducers are more difficult to miniaturize, making their application more restricted compared to piezoelectric transducer. The piezoelectric crystals are obtained from doped layers of Zirconate Titanate (PZT 5H), having a high degree of minimization and can be designed Jos´ e E. Q. Souza is Marter Degree student in Federal University of Bahia-UFBA, Brazil. Antonio C. C. Lima is a full Proectrical Engineering and a full Professor in the Department of Electrical Engineering, at Federal University of Bahia FBA, Bahia, Brazil (e-mail: mfontanaacdcl@ufba.br, acdcl@ufba.br). in different ways, that gives the adaptability and versatility characteristic to the device [10]. The generators built for vibration energy harvesting are designed with the primary purpose of spreading the vibration in order that the system is in resonance with the operating frequency of the equipment in which it is coupled. There are two simple configurations that are typically used as the basis for energy harvesting generation, these are defined as a single support or double support cantilever structure [11]. Each type of generator has different properties such as the operating frequency range, signal amplitude generated and bandwidth of generation capacity. This paper presents the piezoelectric micro-generator characterization for energy harvesting application. We performed the characterizations of the piezoelectric micro-generator for a linear and angular mass distribution relative to the attachment point. The paper is organized as follows. The second section describes the experimental procedures. The third section overviews the micro-generator principles used in this work. The results and discussions are presented in the fourth section, and conclusions are drawn in the last section. II. EXPERIMENTAL PROCEDURES Figs. 1 (a) and (b) show the schematic block diagram and the low-cost experimental prototype for an alternative piezoelectric micro-generator prototype for energy harvesting application, respectively. The experimental setup was composed by a computer, data acquisition system, audio amplifier, speaker, bushing, mass and piezoelectric capsule. A piezoelectric capsule (model: 7BB-35-3L0, brass plate: 35mm, resonant frequency: 2.8kHz, resonant impedance = 200Ω and capacitance: 30nF at 1kHz) produced by muRata Company and a speaker (model: 20120911, diameter 6.5 inch, impedance 4Ω, maximum power: 90W) produced by Sony Inc were used as main parts of experimental setup. Two National Instruments multifunction data acquisition system (NI DACX) modules (NI-9205 and NI-9263) were used. The NI-9205 module is 32-channel, 200mV to 10V, 250kS/s, 16-Bit analog input converter, and the NI-9263 is an analog output module composed 4-channel, 10V, 16 Bit, 100kS/s/ch. An acquisition software was developed in LabVIEW to generate excitation signal input (type: sine signal, peak-to-peak voltage: 1V, offset voltage: 0V) at frequencies ranging from 10Hz to 160Hz, and to storage of the voltage and current signals of the piezoelectric. We used a total mass of 2.6g to realize all experiments and measurements of the piezoelectric micro-generator World Academy of Science, Engineering and Technology International Journal of Energy and Environmental Engineering Vol:12, No:8, 2018 527 International Scholarly and Scientific Research & Innovation 12(8) 2018 scholar.waset.org/1307-6892/10009350 International Science Index, Energy and Environmental Engineering Vol:12, No:8, 2018 waset.org/Publication/10009350