LITERATURE REVIEW

INTRODUCTION:

Electricity is a very important thing of our daily life. Without electricity it will be ruined our activities not just for ourselves but also for industrial. But lately, our populations also increase and the decaying of the natural resources energy crisis is becoming a very serious issue all over the world. As example on this crisis based on the whole world is we are dependent upon the fossil fuels for electricity. With a sort time maybe we can use this, but if it still using a fossil for electricity on a long time  it will be eliminated and soon they will be no longer available which is again very serious issue for our upcoming generation.    

JOURNAL 1:

There are a number of approaches being used to generate alternative power supply. One of the method is piezoelectric smart road sensor[1]. On application of mechanical stress on piezo materials equivalent amount of electric current or voltage is produced. This effect can be used in harvesting energy from the smart roads. Priyanshu et.al. says that when any vehicle moves on the roads it produces very small vertical deformations and vibrations on the roads. The increasing demand of the electricity forces us to think about harvesting that vibration energy from vehicles which is wasted otherwise. Also the traffic on the roads has increased to a certain level that if we employ such sensors on the roads it will be a great support in reducing the burden of the fossil fuels.

Energy can be harvested from various energy sources like radiations, light, temperature, vibrations etc. Vibrations are created from different sources like from machines in industrial, moving vehicles on streets and so on. Vibration to electrical energy is changed over by utilizing three distinct ideas i.e. Electromagnetic, Electrostatic and Piezoelectric[2]. The piezo impact created is because of the adjustment in the electric polarization of the materials due to the apply stress which prompts the production of electric current or voltage. The piezoelectric effect was proposed by the curie brothers according to which electric charge is produced, when force is applied parallel to polar axis using crystals of tourmaline, quartz, topaz, cane sugar and Rochelle salt[3]. Piezoelectric crystal are normally happening stable crystal until any outside forces are connected to them. Piezoelectric effect is a  reversible process. It can happen in two ways i.e. coordinate piezoelectric effect and speak piezoelectric effect.

JOURNAL2:

Another journal is [4] Some vibration based energy generators that converts mechanical energy to electrical energy that have been successfully developed are Electromagnetic[5], Electrostatic[6], Piezoelectric generators[7],[8]. There are two effects in piezoelectricity: direct piezoelectric effect and converse piezoelectric effect. Direct piezoelectric effect is the generation of electric charge when mechanical strain is applied on piezoelectric materials; whereas the converse effect is defined as the deformation in the crystal caused, when an electrical voltage is applied to the piezoelectric materials. Direct piezoelectric effect is employed in manufacturing sensors and converse piezoelectric effect is employed in manufacturing actuators. The piezoelectric materials are of natural and also of artificially made. Quartz is a natural piezoelectric material while Lead Zirconate Titanate (PZT) is an artificial piezoelectric material. PZT piezoelectric sensor can be used for small scale energy harvesting because of its high energy storage density[9].

         JOURNAL 3:

Other than that, for research journal is [10].The requirement for a wireless electrical power supply has impelled  an enthusiasm for piezoelectric energy collecting, or the extraction of electrical energy utilizing a vibrating piezoelectric device. Examples of applications that would benefit from such a supply are a capacitively tuned vibration absorber [11],a foot-powered radio “tag” [12], [13], and a PicoRadio [14]. Vibrating piezoelectric device varies from an average electrical power source in that its inner impedance is capacitive rather than inductive in nature, and that it might be driven by mechanical vibrations of changing amplitude and frequency.

On this journal described herein was to develop an approach that maximizes the power transferred from a vibrating piezoelectric transducer to an electrochemical battery. Other than that it is straightforward model of a piezoelectric transducer. An ac–dc rectifier is included what is more, the model is utilized to decide the purpose of ideal power stream for the piezoelectric element. To decide its power flowcharacteristics, a vibrating piezoelectric component is displayed as a sinusoidal current source i_p(t)  in parallel with its inward electrode capacitance C_p.