Chapter 1: INTRODUCTION
Chapter 2: LITERATURE SURVEY
2.1 AVAILABLE ENERGY SOURCES IN THE ENVIRONMENT
2.2 EXAMPLES OF COMMON VIBRATION SOURCES
2.3 VOLTAGE MODE AMPLIFIER
2.4 PIEZOELECTRIC MATERIAL
Chapter 3: SYSTEM DEVELOPMENT/DESCRIPTION
3.1 COMPONENTS USED
3.2 ENGINEERING DESIGN PROCESS
3.3 PIEZOELECTRIC TECHNOLOGIES
3.4 LED TECHNOLOGY
3.5 FUTURE SCOPE
Chapter 4: PERFORMANCE ANALYSIS/OPERATION
Chapter 5: APPLICATIONS OF ENERGY HARVESTING THROUGH
5.1 Power Walking With Energy Floors
5.2 Piezoelectric road harvests traffic energy to generate electricity
5.3 Public Areas
Chapter 6: RESULTS & CONCLUSION
Chapter 7: REFERENCES
Our main aim is to produce light out of the force or stress applied on the piezoelectric sensor.
This can solve many problems regarding the dependency on the replenishing sources of
energy, by harvesting energy, since the world is in need of energy.
This produced light could be the solution for:
1. Growing need for renewable sources of energy,
2. Reduce dependency on battery power,
3. Lights can be used in automobiles, footwear, etc..
Today, the energy harvesting from light, thermal, magnetic or mechanical
energy in the ambient environment is an important research topic. With recent
progresses in wireless, sensor systems are being popularly used in various areas,
including human body care, bridge or engine early health monitoring etc. .
However, replacement of small power supplies and batteries in sensor systems would
be a tedious task. Therefore, it is quite interesting to supply a small amount of power
for sensor systems from environmental energy.
In addition, because of the shortage in energy sources, people are also seeking
environmental energy to replace part of the electric energy used in daily life.
Therefore, another interesting application is to harvest the mechanical energy from
highway or railway for generating electric energy, which may supply a small to
medium amount of power for powering road lights or even electric motors if there are
enough vehicles/trains running.
One of the most effective methods for power harvesting systems is to use
piezoelectric materials to convert mechanical vibration or strain energy to electric
energy based on the piezoelectric effect. During the past ten years, there has been an
explosion of research in the area of harvesting energy from ambient vibrations by
using the direct piezoelectric effect. Piezoelectric materials are very good prospects
for mechanical energy conversion because they have a good electromechanical
coupling effect. Piezoelectric energy harvesting devices are also much simpler than,
for example electromagnetic or electrostatic devices.
For these reasons, piezoelectric energy harvesting devices have attracted much
attention. Conventional piezoelectric harvesting devices are based on a piezoelectric
unimorph or bimorph cantilever configuration i.e., one or two piezoelectric elements
laminated with one long elastic plate, and they are operated in bending mode. In
general, piezoelectric cantilever type harvesters generate only a very small power
output, and they cannot work under pressure.
In 2004, Uchino’s group at Pennsylvania State University developed a
piezoelectric cymbal transducer which operated in flextensional mode for vibration
energy harvesting, which could work well under a small force load.
1.2 PIEZOELECTRIC EFFECT
There are certain materials that generate electric potential or voltage when
strain is applied to them, they tend to change their dimensions. This is called
piezo electric effect.
This effect was discovered in the year 1880 by Pierre and Jacques Curie.
The piezoelectric transducers work on the principle of piezoelectric effect. When
mechanical stress or forces are applied to some materials along certain planes, they produce
The voltage output obtained from these materials due to piezoelectric effect is proportional to
the applied stress or force.
1.3 NEED OF ENERGY HARVESTING
• Growing need for renewable sources of energy
• Proposes several potentially inexpensive and highly effective solutions
• Reduce dependency on battery power
• Complexity of wiring
• Increased costs of wiring
• Reduced costs of embedded intelligence
• Increasing popularity of wireless networks
• Limitations of batteries
• Reduce environmental impact
1.4 PIEZOELECTRIC MATERIAL (Material with Piezo properties):
1.4.1 Naturally occurring crystals:
Berlinite (AlPO4), Cane sugar, Quartz, Rochelle salt, Topaz, Tourmaline Group
Minerals, and dry bone (apatite crystals)
1.4.2 Man-made ceramics:
Barium titanate (BaTiO3), Lead titanate (PbTiO3), Lead zirconate titanate
(Pb[ZrxTi1-x]O3 0<x<1) - More commonly known as PZT, Potassium niobate (KNbO3),
Lithium niobate (LiNbO3), Lithium tantalate (LiTaO3), Sodium tungstate (NaxWO3),
Polyvinyledene fluoride (PVDF)
2 LITERATURE SURVEY
2.1 PYROELECTRIC EFFECT
When the temperature of the material is changed, an electric potential appears between the
terminals: this is called the pyroelectric effect.
2.2 PIEZOELECTRIC FILMS
Piezoelectricity can be obtained by orienting the molecular dipoles of polar polymers
such as PVDF in the same direction by subjecting films to an intense electric filed: this is the
polarization. The polarized electrets are thermodynamically stable up to about 90°C.
PVDF is particularly suitable for the manufacture of such polarized films because of
its molecular structure (polar material), its purity – which makes it possible to produce thin
and regular films – and its ability to solidify in the crystalline form for polarization.
2.3 PROPERTIES OF PVDF PIEZOELECTRIC FILMS
Flexibility (possibility of application on curved surfaces) High mechanical strength
High and stable piezoelectric coefficients over time up to
approximately 90°C Characteristic chemical inertness of PVDF Continuous polarization for
great lengths spooled onto drums Thickness between 9 microns and 1 mm.
2.4 COMPONENTS USED
Piezo electric cells.
One aluminium metal sheet.
Piezo Electric Cells
2.4.1 Piezoelectric Cell
The piezoelectric cell is what allows us to convert the mechanical energy to electrical
energy thus, utilizing our wasted energy. The piezoelectric inputs the energy from the input
signal and outputs the signal to our circuit system. We will buy this component as it is too
physically advanced for us to construct and we do not have the tools to construct it.
The principle of operation of a piezoelectric sensor is that a physical dimension,
transformed into a force, acts on two opposing faces of the sensing element. Depending on
the design of a sensor, different "modes" to load the piezoelectric element can be used:
longitudinal, transversal and shear Detection of pressure variations in the form of sound is
the most common sensor application, e.g. piezoelectric microphones (sound waves bend the
piezoelectric material, creating a changing voltage) and piezoelectric pickups for Acousticelectric guitars.
A piezo sensor attached to the body of an instrument is known as a microphone.
Piezoelectric sensors especially are used with high frequency sound in ultrasonic transducers
for medical imaging and also industrial nondestructive testing (NDT).
As very high electric fields correspond to only tiny changes in the width of the
crystal, this width can be changed with better-than-μm precision, making piezo crystals the
most important tool for positioning objects with extreme accuracy — thus their use in
actuators. Multilayer ceramics, using layers thinner than 100 μm, allow reaching high electric
fields with voltage lower than 150 V.
These ceramics are used within two kinds of actuators: direct piezo actuators and
Amplified piezoelectric actuators. While direct actuator's stroke is generally lower than 100
μm, amplified piezo actuators can reach millimeter strokes.
2.4.4 DC Converter
Our converter, an AC/DC converter, inputs an AC source and outputs a DC source.
We need a DC source because if we decide to power an energy storage device we will need
to provide that with a DC source. Our AC/DC converter is built from a bridge rectifier type
schematic (see schematic) since an AC/DC IC was not available. This block is also
responsible for protecting our circuit from reverse currents, through the use of diodes. This
block receives its signal from the piezoelectric.
However, there is a lot of communication within the block as this is where the real
circuitry that runs our system is built. It is at this block that we no longer have mechanical
energy, but electrical energy, which is output to whatever our output may be, whether an
LED sign or energy storage device.
Here we amplify the current since we are expecting it to be very small. . Since we
have a capacitor bank this dissipation will last longer than if we simply had a direct
connection to our converter and amplifier. Thus, our LEDs, or whatever our output source is,
will have power supplied for a long period of time. We can also test the efficiency of our
energy storage by simply monitoring the time that the output device runs for to see whether
or not our storage elements actually behaves the way we expect it to and prolongs the ―ON‖
period of our LEDs longer than if the LEDs, or other output Storing and amplifying our
energy can be achieved with a circuit that contains capacitors and an op-amp.
We may also use a few super capacitors; however we feel that the best approach will
be a capacitor bank. We will need to test the components to find out which chips are suitable
with our circuit since we need capacitors that are properly rated for our system requirements.
We will test this by measuring our power usage with PSPICE simulations as well as
direct measurements from our piezoelectric rods to see the voltage produced. Combining this
information we will have an exact idea of what value of capacitors we will need to use in our
capacitor bank. Our capacitor bank will be a certain number of capacitors connected in
Each capacitor will take in a small amount of current at a time, this is distributed
amongst the capacitors fairly evenly, although not exact since no capacitor has the exact
same value. Then our output device, the LEDs will be powered by the current dissipating
from our capacitors device, was connected straight to our converter and amplifier. Our
amplifier is very simple. Its purpose is to amplify the current, thus also reducing the voltage,
so that we have more power at our output since we need a higher current to drive any device
than the current we get directly from the piezoelectric rods. We can test our energy device as
mentioned above and we can test our amplifier through simulating it in PSPICE to see what
the best resistor combination would be to give us the right current for our output.
2.5 PIEZOELECTRIC TECHNOLOGIES
According to How Stuff Works, piezoelectric materials create a positive and a
negative End when work is done to deform their original shape. The International Harvest
Tribune Claims that ―energy harvesting‖, more commonly referred to as ―crowd farming‖,
has been in Existence for as long as 10 years. An electrical charge flows across the material
once pressure is relieved from them. While they usually provide very low currents, they can
generate extremely high voltages.
Harvesting energy from piezoelectric flooring is said to be impractical in residential
applications due to the high cost of implementation and small
amount of electricity
generated in these settings. Common piezoelectric materials include quartz, Rochelle salt,
and some ceramics. The New York Times also claims that harvesting energy from
piezoelectric materials is inefficient, converting only a small amount of kinetic energy into
The Christian Science Monitor claims that a single footstep could potentially generate
enough electricity to power two 60-watt incandescent bulbs for one second, while the
International Herald Tribune claims that the technology were implemented in a busy train
station that the energy captured could power 6,500 LED lights for an unspecified amount of
2.6 LED TECHNOLOGY
Light-emitting diodes, or LEDs, show promise for replacing traditional lighting
sources. According to the Christian Science Monitor, the European Union has banned the
sale of incandescent light bulbs because of their inefficiencies, with BBC News stating that
Australia has followed suit and banned them as well. Specifically, they cite that the standard
incandescent light bulb converts only about five percent of the electricity it uses into usable
light, with the rest being converted into heat. LEDs are approximately four times more
efficient than incandescent light bulbs and currently as efficient as fluorescent lighting
without the environmentally harmful mercury content that they contain according to Purdue
LEDs also carry the benefit of providing high visibility in signs, some of which can
be seen from up to 1.5 kilometers away, claims Wallstreet Pit. The New York Times states
that a new LED sign in New York City will be bright enough to be readable even during high
Philips claims that their current state-of-the-art Luxeon K2 LEDs have outputs of at
least 200 lumens at 12 volts DC with a current as little as 350 mA. Further, they dim far less
than traditional lighting sources, with some experiencing only a 10% loss of light output after
as many as 1,000 hours, and last for as long as 15 years under normal usage conditions.
Several cities are considering switching from high pressure sodium lighting to LED lighting,
including a pilot program of 34,000 street lamps slated for testing in Lansing, Michigan.
2.7 PIEZOBASED POWER GENERATION
After doing several experiments regarding piezobased power generation Umedal
sought after a device that would eliminate the need to charge up portables before taking them
The device would charge the mobile device enroute while traveling.
accomplish this, they constructed a piezo-generator that transforms mechanical impact
energy to electrical energy by using a steel ball which impacts the generator.
The steel ball is initially 5mm above a bronze disk . The ball falls and strikes the
center of the disk producing a bending vibration. The ball continues to bounce on the disk
till it stops. The piezo patch converts the vibrational energy of the bouncing ball to electrical
energy and stores a voltage in a capacitor. They performed analyses on two things. The first
case was on the first impact. The second case was on multiple impacts from the ball.
For the first case, higher voltage and capacitance affects the generator. A higher
voltage decreases the time during which the current flows. If the capacitance is small, the
voltage will go up quickly, limiting the time current will flow. On the other hand, if the
capacitance is large, it takes time for the voltage to build up and allows the current to flow
for more time. For the second case, the capacitance affects multiple impacts the same way it
does for a single impact.
3 SYSTEM DEVELOPMENT
3.1 ENGINEERING DESIGN PROCESS
3.2 PVDF SENSOR PRICES LIST
3.3 TYPES OF BUZZERS
3.3.1 AC BUZZER
3.3.2 DC BUZZER
3.5 SPECIFICATIONS AND CHARACTERSTICS
3.6 AVAILABLE ENERGY SOURCES IN THE ENVIRONMENT
3.7 EXAMPLES OF COMMON VIBRATION SOURCES
3.8 VOLTAGE MODE AMPLIFIER
4 PERFORMANCE ANALYSIS
4.1 MAIN CIRCUIT
The piezoelectric transducers work on the principle of piezoelectric effect.
When mechanical stress or forces are applied to some materials along certain planes,
they produce electric voltage.
This electric voltage can be measured easily by the voltage measuring instruments,
which can be used to measure the stress or force.
By applying the mechanical load to piezoelectric path,the energy converts into
When a capacitor is connected to electric board,the energy get stored in the capacitor.
The electric board is connected to the LED module which emits light.
Finally the photo diode measures the intensity of light.
The voltage output obtained from these materials due to piezoelectric effect is
proportional to the applied stress or force.
The output voltage can be calibrated against the applied stress or the force so that the
measured value of the output voltage directly gives the value of the applied stress or
The voltage output obtained from the materials due to piezoelectric effect is very
small and it has high impedance.
To measure the output some amplifiers, auxiliary circuit and the connecting cables
An Electric potential is developed across the face, and this electric potential is used to
produce electric current which is used to glow the lights, LED,s, and further this we
can charge the battery of our mobile or cellphones by connecting the device to the
cellphone via. some USB device.
The diagram showing that as the pressure is applied to the faces there is a generation
of electric current which is indicated by the Galvanometer.
Pressure is applied to the Faces there is a Generation of Electric Current which is indicated
by the Galvanometer.
4.3 PRECAUTIONS FOR USE
• Do not apply DC bias to the piezoelectric buzzer; otherwise insulation resistance may
become low and affect the performance.
• Do not supply any voltage higher than applicable to the piezo- electric buzzer.
• Do not use the piezoelectric buzzer outdoors. It is designed for indoor use. If the
piezoelectric buzzer has to be used outdoors, provide it with waterproofing measures; it will
not operate normally if subjected to moisture.
• Do not wash the piezoelectric buzzer with solvent or allow gas to enter it while washing;
any solvent that enters it may stay inside a long time and damage it.
• A piezoelectric ceramic material of approximately 100µm thick is used in the sound
generator of the buzzer. Do not press the sound generator through the sound release hole
otherwise the ceramic material may break. Do not stack the piezoelectric buzzers without
• Do not apply any mechanical force to the piezoelectric buzzer; otherwise the case may
deform and result in improper operation.
• Do not place any shielding material or the like just in front of the sound release hole of the
buzzer; otherwise the sound pressure may vary and result in unstable buzzer operation. Make
sure that the buzzer is not affected by a standing waves or the spikes.
• Be sure to solder the buzzer terminal at 350°C max.(80W max.)(soldering iron trip) within
5 seconds using a solder containing silver.
• Avoid using the piezoelectric buzzer for a long time where any corrosive gas (H2S, etc.)
exists; otherwise the parts or sound generator may corroded and result in improper operation.
• Be careful not to drop the piezoelectric buzzer.
4.4 ESTIMATION OF ELECTRIC CHARGE OUTPUT FOR PIEZOELECTRIC
One method of power harvesting is to use piezoelectric materials, which form
transducers that are able to interchange electrical energy and mechanical strain or force.
Therefore, these materials can be used as mechanisms to transfer ambient motion (usually
vibration) into electrical energy that may be stored and used to power other devices.
By implementing power harvesting devices, portable systems can be developed that
do not depend on traditional methods for providing power, such as the battery, which has a
limited operating life. A significant amount of research has been devoted to developing and
understanding power harvesting systems .
The power harvesting system used the energy generated by the PVDF to charge a
capacitor and power a transmitter that could send information regarding the strain of the
beam a distance of 2m. Their model has been experimentally verified using a 1-d beam
structure with peak power efficiencies of approximately 20%.
Most of the previous studies all realized that the energy generated by the piezoelectric
material must be accumulated before it can be used to power other electronic devices.
High frequency response: They offer very high frequency response that means the
parameter changing at very high speeds can be sensed easily.
High transient response: The piezoelectric transducers can detect the events of
microseconds and also give the linear output.
The piezoelectric transducers are small in size and have rugged construction.
Some of the limitations of piezoelectric transducers are:
1) Output is low: The output obtained from the piezoelectric transducers is low, so
external electronic circuit has to be connected.
2) High impedance: The piezoelectric crystals have high impedance so they have to
be connected to the amplifier and the auxiliary circuit, which have the potential to
cause errors in measurement. To reduce these errors amplifiers high input impedance
and long cables should be used.
3) Forming into shape: It is very difficult to give the desired shape to the crystals with
5 RESULTS & CONCLUSIONS
Intensity of light
5.2 FUTURE SCOPE
Series Piezoelectric materials embedded on road to glow the road lights as shown :
In this figure we see the piezoelectric cells are embedded on the whole road and these
embedded piezoelectric cells are connected with external charge storing device with the help
of connectors, and the charge so developed are then supplied to all the street lights as shown
in the figure.
Economically competitive with the traditional carbon-based energy production.
The electrical storage system, which is integrated in the roads, rail roads, and runways,
does not take up any new public space and functions in all weather conditions.
Once embedded into road ways or railways, generators require minimal maintenance.
These solutions can also serve as information gatherers in future ―smart roads‖ measuring
a truck or rail car’s weight in real time, send data back through a self-powered’ wireless
connection. These could be used in weighing stations.
5.3.1 Cigarette Lighter
Pressing the button causes a spring-loaded hammer to hit a piezoelectric crystal,
producing a sufficiently high voltage electric current that flows across a small spark-gap, thus
heating and igniting the gas.
5.3.2 Armed Forces
The armed forces toyed with the idea of putting piezoelectric materials in soldier’s
boots to power radios and other portable electronic gear.
5.3.3 Night Clubs
Several nightclubs, mostly in Europe have already begun to power their strobes and
stereos using the force of hundreds of people pounding on piezoelectric lined dance floors.
Several gyms, notable in Portland and a few other places are powered by a
combination of piezoelectric set ups and generators set up on stationary bikes.
Piezoelectric Powered Music Instruments
5.3.5 Harvesting From Human Body
Capitalizing on the friction and heat created by walking, running and even just
wearing jeans, engineers from Michigan Technological University, Arizona State University
devised a way to use this type of generated energy to charge portable electronic devices, like
iPods and mobile phones.
5.3.6 Piezoelectric road harvests traffic energy to generate electricity
Isreali engineers are about to begin testing a 100 metre stretch of roadway embedded
with a network of Piezo Electric Generators (IPEG™). The piezoelectric effect converts
mechanical strain into electrical current or voltage and the system is expected to scale up to
400 kilowatts from a 1-kilometre stretch of dual carriageway. The IPEG™ is a pioneering
invention in the field of Parasitic Energy harvesting and generates energy from weight,
motion, vibration and temperature changes and will certainly have other parasitic energy
harvesting applications in many fields. Initially though, the system can be configured to
generate and store energy from roads, airport runways and rail systems at the same time as
delivering real-time data on the weight, frequency and spacing between passing vehicles. The
harvested energy can be transferred back to the grid, or used for specific public infrastructure
purposes such as lighting and widespread use of the system would enable far greater scrutiny
and hence understanding of the behaviour of road vehicles.
As such, the embedding of piezoelectric generators to create "smart roads" could
eventually become an integral part of traffic management systems.
The harvesting system of parasitic mechanical energy from roadways is based on the
piezoelectric effect converts mechanical strain into electrical current or voltage. The
harvested energy can be transferred back to the grid, or used for specific road infrastructure
purposes. The infrastructure captures and stores energy for reuse.
The generators are mounted with electronic cards supplying the storage system. The
laying of the present system, (embedding the generators and electronic cards in to the
roadway), can be done during paving of new roads or in the course of the maintenance work
in existing roadways, so it’s entirely retrofittable to any road, and the heavier the vehicle, and
the greater the number of vehicles, the greater the return, all the way to electricity production
on an industrial scale.
This means that parasitic energy of busy roads, railroads and runways near population
centres can be converted into electrical energy that can run public lighting, or fed back into
5.3.7 Power Walking With Energy Floors
Power walking isn’t just a health craze - it could produce electrifying results!
Energy Floors, a Netherlands-based company, wants to be a player in the sustainable
energy market. They don’t just talk the talk, they walk the walk … literally. Their products,
the Sustainable Energy Floor and Sustainable Dance Floor, convert footsteps into electricity.
As a person steps on an Energy Floor tile, the tile flexes about 10 mm. That
movement is converted into electricity - 15 Watts on average, and up to 25 Watts peak. The
tiles are modular; connect 40 tiles together and the network can generate up to 1 kW. They
wouldn’t give me details on the generator, except to say that it’s not piezoelectric. Based on
the diagram below, it looks like a rack-and-pinion that drives a small permanent magnet
In addition to the tiles, the system includes a controller module that directs the flow of
electricity. The 12V output can light LEDs (as in the Sustainable Dance Floor or a lighted
walkway), power an external low-voltage device, or charge a battery.
5.3.8 Public Areas
Blocks that light up when activated entice people to step on them. Put a few at each
shopping mall and you have a playground that lets kids burn off their excess energy and turn
it into electricity. Set them up in front of the stage at a Phish concert and you might generate
enough electricity to power the amps during one of Trey Anastasio’s guitar solos. (Okay maybe that one is a little ambitious.)
But it’s not just a high-tech toy. Energy Floors recently partnered with the Russian
Railway Research Institute, which hopes to put Energy Floors on railroad platforms and
They’ll also investigate the use of this technology to harvest energy from the
movement of cars and trains. Frankly, I think piezoelectric transducers might be better for
those applications. They’re less efficient than electromagnetic generators, but they might be
more durable under heavy vehicular traffic.
In keeping with the company’s sustainable focus, the floor tiles are made from
recyclable materials. They have a 30 year expected lifetime.
When the pressure is applied on the face of the device, there is a deformation of
charge carriers inside the crystals which will result in Electric field, and therefore an Electric
potential is developed across the face, and this electric potential is used to produce electric
current which is used to glow the lights, LED,s, and further this we can charge the battery of
our mobile or cell phones by connecting the device to the cell phone via. some USB Device.
The ability of piezoelectric equipment to convert motion from human body into electrical
power is remarkable.
It is a great hope that energy harvesting will rule the next decade in the technical field.
We thereby conclude upon the project by generating light out of the stress applied on the
piezoelectric material.This can solve many problems regarding the dependency on batteries,
also to harvest energy , since the world is in need of energy.
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