VIBRATION ENERGY HARVESTING
PROJECT REFERENCE NO: 39S_BE_1248
COLLEGE
: GOVERNMENT ENGINEERING COLLEGE, HUVINAHADAGALI,
BELLARY
BRANCH
: DEPARTMENT OF MECHANICAL ENGINEERING
GUIDE
: MR. SURESH K
STUDENTS : MR.MAHESH
MR.PRASHANTHKUMAR
MR.MOHANKUMAR A V
MS.ANITHA K
INTRODUCTION:
In our world today, we are unmistakably moving towards a technological way of life.
More and more are carrying portable electronic devices than ever before. These devices allow for
unbelievable power and versatility in communication and problem solving. But, as the
technology for portables has grown tremendously, battery and energy storage technology has not
kept up. New technology allows for these portables to become smaller, but battery size remains
the same. Perhaps sometimes the battery must be larger in order to accommodate the greater
power demands by a portable device. An alternative for batteries is to create energy while on the
go. Using piezoceramic materials (PZT) is one way we can accomplish this. Piezoelectrics are
the most popular smart materials. Piezoelectric materials have found widespread application as
transducer those are able to change electrical energy into mechanical motion or force or vice
versa, which are possible to harvest energy from vibrating structures.
With the recent advances in wireless and MEMS technology, the demand for portable
electronics and wireless sensors is growing rapidly. Since these devices are portable it becomes
necessary that they carry their own power supply. In most cases this power supply is the
conventional battery, however problems can occur when using batteries because of their finite
lifespan. For portable electronics replacing the battery is problematic because the electronics
could die at any time and replacement of the battery can become a tedious task. In the case of
wireless sensors, these devices can be placed in very remote locations such as structural sensors
on a bridge or GPS tracking devices on animals in the wild. When the battery is extinguished of
all its power, the sensor must be retrieved and the battery replaced.
Due to the remote placement of these devices obtaining the sensor simply to replace the
battery can become a very expensive task or even impossible. For instance, in civil
infrastructure applications it is often desirable to embed the sensor, making battery replacement
unfeasible. If ambient energy in the surrounding medium could be obtained, then it could be
used to replace or charge the battery. One method is to use piezoelectric materials to obtain
energy lost due to vibrations of the host structure. This captured energy could then be used to
prolong the life of the power supply or in the ideal case provide endless energy for the electronic
devices lifespan. Due to these reasons, the amount of research devoted to power harvesting has
been rapidly increasing. This paper will review and detail some of the topics in power
harvesting that have been receiving the most research, including energy harvesting from
mechanical vibration.
OBJECTIVE:






To understand the concepts of vibrations
To understand the concepts Energy Harvesting
To understand the concepts of new emerging smart materials
Analysis of vibrational Energy Harvesting by Piezoelectric material (PZT)
Electrical Energy is stored in the storage system or Battery which can be used for
glowing LEDs
The main aim of this project is to generate the electrical energy from the vibrating
structures.
METHODOLOGY:
Block Diagram:
Figure: Typical block diagram arrangement of vibration energy harvesting system
1. Signal Conditioner: Converts constant 230V, 50Hz Power supply to variable voltage and
frequency ranging from 50V to 120V and 15Hz to 75Hz respectively.
2. Actuator: Piezoelectric (PZT) material is used as actuator. The output of the Signal
Conditioner is Input to the Actuator, converts electrical energy to mechanical vibrations
of beam.
3. Vibrating Beam: Cantilever type beam is considered which gives more strain at fixed end
which is useful for the sensor to generate more electrical charges on its surface.
4. Sensor: Piezoelectric (PZT) material is used as sensor (transducer). Converts mechanical
vibrational energy of the beam into electrical energy by generating charges on its surface.
5. Battery: It is the storage device which stores the electrical energy generated by the sensor
and it can be used for further applications.
Line Diagram:
Notations:
1- Sensor(PZT)
2- Actuator(PZT)
3- Aluminum beam
4- Load
5- Switch to power oscillator
6- Voltage input display
7- Frequency input display
8- Frequency adjusting nob
9- Voltage adjusting nob
Properties and Dimensions
Beam
Parameter
(Aluminium)
Length
Width
Thickness
Young’s
modulus
Length
Width
PZT(SP-5H)
Thickness
Curie temp
Value
0.2m
0.025m
0.003m
70GPa
0.072m
0.025m
0.001m
190 degrees
RESULT AND CONCLUSION:
It is experimented for different inputs, these are few results or outputs from the above
experiment
Table.1
Voltage(V)
50
Current
(µA)
Frequency(Hz)
20
17.9
25
26.4
30
30.5
35
59.5
40
11.4
45
25.5
50
32.2
55
37.3
60
41.6
65
45.1
70
51.1
73
54.0
75
51.3
70
90
110
Power
(mW)
Current
(µA)
Power
(mW)
Current
(µA)
Power
(mW)
Current
(µA)
Power
(mW)
0.179
0.264
0.305
0.595
0.114
0.255
0.322
0.373
0.416
0.451
0.511
0.540
0.513
26.3
37.5
43.5
86.0
17.0
37.0
45.8
53.0
59.6
65.8
72.3
76.5
73.1
0.263
0.375
0.435
0.860
0.170
0.370
0.458
0.530
0.596
0.658
0.723
0.765
0.731
34.4
50.7
57.4
109.4
23.5
48.2
60.3
70.2
78.9
84.6
95.0
100.7
95.5
0.344
0.507
0.574
1.094
0.235
0.482
0.603
0.702
0.789
0.846
0.950
1.007
0.955
42.5
60.3
64.8
128.4
32.7
60.8
74.4
86.0
96.4
105.6
117.3
127.9
117.2
0.425
0.603
0.648
1.284
0.327
0.608
0.744
0.860
0.964
1.056
1.173
1.279
1.172
As per the above readings, a graph is plotted input frequency v/s output power.
From the graph at 50V as input it is observed that the power increases as frequency
increases, as frequency reaches natural frequency 35Hz the power generated increases
drastically, the maximum value of power obtained at this combination of voltage and frequency
is 0.595 mwatts. As frequency increases beyond the natural frequency the power generated
decreases because the strain in beam reduces as amplitude of vibration decreases.
Similarly at 70V, 90V and 110V as input the power generated is 0.86mwatts,
1.094mwatts and 1.284mwatts respectively.
FUTURE WORK:
Harvesting energy from vibration is one of the most promising technologies, hence it has
wide scope in future, as this setup is considered, it is just a prototype where actually vibrations
are created by piezoelectric actuator but in fact it has to be used directly where the vibrations are
already present.
Since it is possible to capture energy from various parts of the human body such as
Walking, cycling, arm movements, finger pressure, respiration and blood pressure, one of the
future associated applications will be the development of a human battery that extracts electricity
from glucose of the blood, capable of generating up to 100W-A future trend on this applications
of energy harvesting methods in portable medical devices is performed.
Further the research can be carried out by using piezoelectric polymers which are more
flexible when compared to piezoelectric crystals, where the vibrations with larger amplitudes can
be given as an input to obtain the more power. It has the vast applications in future.
From the subtle vibrations of floors and walls that nearby machinery causes to the severe
excitation of an automobile chassis or jet engine housing, mechanical stimuli are common in
many settings but can vary widely in frequency and amplitude. Inventors have long designed
systems to harvest this energy.
As an alternative to conventional cantilevered beams, the L-shaped beam mass structure
as a new piezoelectric energy harvester configuration. This structure can be tuned to have the
two first natural frequencies relatively close to each other, resulting in possibility of a broader
band energy harvesting system.