Modelling and characterization piezoelectric transducer for sound wave energy harvesting

Energy harvesting system is using ambient energy conversion in the environment. The environmental energy will be converted into usable electrical energy that can be used in controlling wireless electronic devices. The available mechanical vibration from the sound energy will then be converted to electrical energy by using a piezoelectric transducer. The size of the piezoelectric represents the surface area of the electrode on the piezoelectric model. A smaller size piezoelectric transducer is unable to produce a good vibration due to the smaller surface area. The bigger dimension of the piezoelectric model would be able to harvest more electrical energy output because the vibration from the bigger piezoelectric model which would able to produce more sound wave energy. The piezoelectric material Lead Zirconate Titanate (PZT-5H) vibration is focused on the resonance frequency at below 1 kHz with sound level decibel is between the range of 35-100 dB. This research is to concentrate on rectangular and trapezium-shaped cantilever. The trapezium shaped cantilever produces higher energy output due to its shape which has better in terms of stress and strain distribution. In addition, researchers have modelled and validated energy harvesters with different proof masses shapes. The improved piezoelectric vibrational energy harvester has a trapezoidal beam and an added triangular proof mass. The arrangement of the piezoelectric tested in parallel, series, combination series and parallel configuration to investigate the performance of the output power generated from the sound wave. The rectangular and trapezium shaped cantilever are resulted in a resonant frequency of 269.4 Hz and 269.88 Hz, respectively. The rectangular and trapezium shaped cantilever produced a maximum output voltage of 3.105 V and 3.635 V respectively. The piezoelectric output during the parallel array configuration, which is 5.636 V, 0.497 mA and 2.803 mW. The output power produced by parallel is 81 % higher than compare in series array configuration and 35.8 % higher than combination of series and parallel. Thus, the produced energy output 5 V would be able to apply at several low power supply applications such as mobile phones, power bank or wireless sensor networks (WSN).