Search

The field of wireless sensors and portable electronics devices gained more attraction and growth over the years. Almost all the devices are powered using chemical batteries. Several energy sources are available in the environment in different parameters, which could be able to convert into an electrical parameter to power the portable devices and wireless sensors. This article reviews the harvesting of vibrational energy and converting it into electrical energy using piezoelectric materials. The sources of energy and conversion mechanism used to convert one type of energy into electrical energy were discussed. The different types of piezoelectric materials, various geometries of the substrate, resonant tuning methods of the harvester, placement of piezoelectric materials, and proof mass on the substrate were also reviewed. [ABSTRACT FROM AUTHOR]

This paper presents the design and development of manual frequency tuneable energy harvester. The energy harvester consists of beam, piezoelectric materials, proof mass, charging circuit, storage device and enclosure box. The design of beam and proof mass was made using the output of previous work and other parts were designed in this work. The energy harvester was developed based on the design and placed into the enclosure box. The fabricated model was tested to know the performance of energy harvester by analysing the output voltage, current, power and charging time of the battery. The distance of proof mass was varied from the fixed end of the cantilever beam to tune the frequency of energy harvester. From the experiment, it was found that the proof mass of energy harvester at 115 mm produced 88.77% more power compared to the proof mass placed at 85 mm from the fixed end. The operating range of energy harvester is about 5 Hz to 30 Hz. The proof mass placed at a distance of 155 mm from the fixed end charge the 60 mAh battery at 65.14% faster compared to the proof mass placed at 85 mm from the fixed end. [ABSTRACT FROM AUTHOR]

This paper presents various designs of the cantilever based piezoelectric energy harvester, which is excited using mechanical vibrations at the fixed end. By varying the geometries of the cantilever beam; higher stress, strain and consequently higher voltage and power could be attained from the same piezoelectric material. The analysis of energy harvesters were done using COMSOL Multiphysics 5.3a. The stress, strain and frequency response of the beams were verified by analytical, numerical and experimental methods. The result shows that the inverted taper in thick and width and inverted taper in width types of beams generated 47.39% and 21.31% more power compared to the rectangular cantilever beam. The resonant frequency of the inverted taper in thick and width beam is 53.3% less than the rectangle beam. [ABSTRACT FROM AUTHOR]

• Effect of placement of piezoelectric material over the length of a cantilever beam was analysed. • Effect of different proof mass material and volume on the performance of energy harvester were analysed. Effect of different orientation of proof mass volume on the performance of energy harvester was analysed. • Maximum power was produced, while the piezoelectric material was placed near to the fixed end. • The material and volume of the proof mass does not have any significant effect on the power output and resonant frequency of the beam. • The placement of the proof mass has a 10.9% effect on the resonant frequency of the beam and shape of the proof mass has 1.9% effect on the power output. This paper presents the effect of placement of piezoelectric material over the length of a cantilever beam based energy harvester. The effect of the material, volume, shape, size and placement of the proof mass were also analysed using COMSOL Multiphysics 5.3a. The distance between the piezoelectric material and the fixed end was varied over the length of the beam. Maximum power was produced, while the piezoelectric material was placed near to the fixed end. The resonant frequency of the beam is decreased, when the distance between the piezoelectric material and the fixed end is increased. The resonant frequency of the energy harvester and the voltage output at various conditions were numerically and experimentally verified. From the numerical analysis, it was found that the material and volume of the proof mass does not have any significant effect on the power output and resonant frequency of the beam. The size of the proof mass has 1.9% and 0.8% effect on the power output and resonant frequency of the beam respectively. The placement of the proof mass has a 10.9% effect on the resonant frequency of the beam and shape of the proof mass has 1.9% effect on the power output. [ABSTRACT FROM AUTHOR]