1 CHAPTER ONE: INTRODUCTION
1.1 Background to the Study
The major source for production of electrical energy has been coal and natural gas which has an
adverse effect on our environment and also require a large amount of capital for startup [1]. The
emergence of more environmental friendly (renewable energy) method of energy production has
been able to reduce the reliability on harmful energy harvester. The most popular form of such
eco-friendly energy production method are through the use of solar and wind [2], their usage are
limited because of lack of continuous availability of solar and wind energy, they both depend of
weather criteria which can be accurately unpredictable also they both require a large amount of
space for installation [2]. An alternative the aforementioned sources of electrical energy is
piezoelectric energy.
Piezoelectric effect is the ability for a material to produce an electrical charge in response to an
applied external force [3]. Piezoelectricity was developed by Pierre Curie and Paul Jacques in 1880
[2]. The word was coined out from two Greek words, “piezin” means to press and “elektron”
meaning an ancient source of electric charge [3]. Piezoelectricity is the generation of electricity
from a material when subjecting it to applied stress [4] [1] [3] [2] or external mechanical energy
such as pressure [4], vibration [2] etc. Piezoelectricity is also the charge stored in certain materials
called piezoelectric materials (such as crystals, certain ceramics, bones, DNA and some proteins)
[5] in response to an applied mechanical energy. When zero force is applied to the piezoelectric
material, its charge are balanced (the positive and negative charges are evenly distributed). But at
the application of force (tension or compression) causing a slight deformation in the lattice
structure of the piezoelectric material which leads to the production of electric charge, which is
accumulated at the surface of the piezoelectric material which can be tapped using a wire [3].
Figure 1: figure illustrating the effect of various type of mechanical stress on a piezoelectric material
There are two types of piezoelectric effect;

Direct piezoelectric effect is the internal generation of electrical energy by the application
of external mechanical stress [3] [2].

Converse piezoelectric effect, the opposite of direct piezoelectric effect, which is the
internal generation of mechanical energy due to the application of an external electric field
[6] [3] [2].
Piezoelectric materials are materials that exhibit piezoelectric effect [6]. They can be used as a
way of converting vibrations into electrical energy that can be stored. They can be classified into
two majorly
I.
Naturally occurring piezoelectric material: These are piezoelectric materials that can be
found readily in nature. They include; belemnite, quartz, cane sugar, Rochelle salt, topaz,
tourmaline group minerals, enamel, dentin, wood, bone, DNA, and various proteins. [5]
[6]
II.
Manmade crystals: They are fabricated by human using various materials of desired
quality. They include; gallium orthophosphate and langasite [6].
Piezo-polymer and piezo-ceramics are the most widely used because of its small size and light
weight. They are used in high voltage and power sources, actuators, sensors [6].
Energy harvesting (also known as energy scavenging) is the process of extracting small amount of
energy that would have been lost as light, heat, vibration [7].
Piezoelec
tric
material
Full wave
bridge
rectifier
Storage
Device
(Battery)
Inverter
AC load
Figure 2: Piezoelectricity energy harvester block diagram

A full wave rectifier is used to convert the Ac output of the piezoelectric material into a DC
voltage.

Inverter converts DC output from battery into AC output so as to power our devices.
1.2 Aims and Objectives
The main object of this project is to build an eco-friendly electrical energy generator using the
energy gotten from mechanical stress which can be used to operate AC loads with little complexity
and no noise. This is to be realized by achieving the following specification objectives:
I.
II.
Design and construction of a footstep generator using PZT 5A.
Implementation of a full wave bridge rectifier.
III.
Implementation of inverter.
IV.
Implementation of digital measuring display for output voltages and battery indication
level.
1.3 Significance of the Study
A foot step generator is just a little application of piezoelectricity. Harnessing electricity through
piezoelectricity is a clean way of generation. It is a forward reach towards the world’s research
of greener technologies that are aimed at protecting the environment. Piezoelectricity has
application over various fields, such as;

The automobile field: Due to the emergence of electric vehicles, researches have been
carried out on how to use piezo electricity as a secondary or emergency source of power
for the vehicle [2] [3]. The generated energy can also be used to power minor electrical
appliances inside a hybrid vehicle [8] such as the dashboard or indoor lightening. The
energy can be generated from the vehicle tyre [6] [1], car damper [5], car chassis. Some
special electric vehicle charging ports have their floored laced with piezoelectric material
which produces the energy that is used to charge the vehicle.

Sports field: New age turfs and artificial fields are being built with piezoelectric materials
being embedded into the turf. This harnesses the kinetic energy of the sportsmen to
generate electrical energy and cater for the power needs such as lightening of the
stadium. There are now jogging shoes with piezoelectric strips embedded into the sole,
the energy harnessed from this strip is stored in a small battery which can be used later to
charge a phone or a small appliance.

Construction Field: Also the concept of piezoelectric floors has been successfully
implemented in places like; Tokyo where the Tokyo station’s ticket gates are floored with
piezoelectric floors which supplies power to the gate [9], a dance club in the United
Kingdom, Club4Climate, also makes use of the piezoelectric floor concept to power
60percent of the clubs power needs [9], a company in Israel, Innowattech, makes use of
the piezoelectric concept beneath the road surface and covering it with layers of asphalt
which generates energy good enough to be fed to the grid [3].
Other domestic application include buzzer.
2 References
[1] S. PATTNAIK, "Design and Analysis of of Piezo-wheel for electric vehicle," Nagpur, India,
2014.
[2] S. Z. A. R. Y. T. Radha D, "Generation of Electricity from Vibration of vehicles," in
International Conference on Electrical, Electronics, Communication, Computer and
Optimization Techniques (ICEECCOT), India.
[3] A. B. Ashish Dakhole, "Electrical Energy Harvesting From Mechanical Pressure of Vehicles
Using Piezoelectric Generators," IOSR Journal of Electrical and Electronics Engineering
(IOSR-JEEE), vol. 12, no. 2, pp. 46-49, 2017.
[4] X. Sun, "An Overview on Piezoelectric Power Generation System for Electricity
Generation.," Journal of Power and Energy Engineering, vol. 5, pp. 11-18, 2017.
[5] S. S. Y. Mukti Nath Gupta, "Electricity Generation Due to Vibration of Moving Vehicles
Using Piezoelectric Effect," Advance in Electronic and Electric Engineering, vol. IV, no. 3,
pp. 313-318, 2014.
[6] D. A.Dinesh kumar, "RENEWABLE ENERGY SOURCE PIEZO ELECTRIC
HARVESTERS IN CAR TYRES.," Online International Confernece on Green Engineering
and Technologies, 2015.
[7] U. \B. R. D. C. M. M. C. S. G. d. P. C. M. O. Renato Caliò, "Piezoelectric Energy
Harvesting Solutions," Sensors, vol. 14, pp. 475-4790, 2014.
[8] S. P. B. F. T. M. K. S. Eckhard Karden, "Energy storage devices for future hybrid electric
vehicles," Journal of Power Sources, vol. 168, pp. 2-11, 2007.
[9] M. M. Behera, "Piezoelectric Energy Harvesting from Vehicle Wheels," International
Journal of Engineering Research & Technology, vol. 4, no. 5, 2015.