16-01-2013, 10:44 AM
Electrical Power Generation Using Piezoelectric Crystal
1Electrical Power.pdf (Size: 41.45 KB / Downloads: 200)
Abstract
The usefulness of most high technology devices such as cell phones, computers, and sensors is limited by the storage capacity of
batteries. In the future, these limitations will become more pronounced as the demand for wireless power outpaces battery development
which is already nearly optimized. Thus, new power generation techniques are required for the next generation of wearable computers, wireless
sensors, and autonomous systems to be feasible. Piezoelectric materials are excellent power generation devices because of their ability
to couple mechanical and electrical properties. For example, when an electric field is applied to piezoelectric a strain is generated and the
material is deformed. Consequently, when a piezoelectric is strained it produces an electric field; therefore, piezoelectric materials can convert
ambient vibration into electrical power. Piezoelectric materials have long been used as sensors and actuators; however their use as electrical
generators is less established. A piezoelectric power generator has great potential for some remote applications such as in vivo sensors,
embedded MEMS devices, and distributed networking. Developing piezoelectric generators is challenging because of their poor source characteristics
(high voltage, low current, high impedance) and relatively low power output. This paper presents a theoretical analysis to increase
the piezoelectric power generation that is verified with experimental results.
INTRODUCTION
echanical stresses applied to piezoelectric materials
distort internal dipole moments and generate electrical
potentials (voltages) in direct proportion to
the applied forces. These same crystalline materials also
lengthen or shorten in direct proportion to the magnitude
and polarity of applied electric fields.
Because of these properties, these materials have long
been used as sensors and actuators. One of the earliest
practical applications of piezoelectric materials was the
development of the first SONAR system in 1917 by Langevin
who used quartz to transmit and receive ultrasonic
waves [1]. In 1921, Cady first proposed the use of quartz
to control the resonant frequency of oscillators. Today,
piezoelectric sensors (e.g., force, pressure, acceleration)
and actuators (e.g., ultrasonic, micro positioning) are
widely available.
The same properties that make these materials useful for
sensors can also be utilized to generate electricity. Such
materials are capable of converting the mechanical energy
of compression into electrical energy, but developing piezoelectric
generators is challenging because of their poor
source characteristics (high voltage, low current, high
impedance). This is especially true at low frequencies and
relatively low power output.
CONCLUSION
As the results shows that by using double actuators in
parallel we can reduce the charging time of the battery
and increase the power generated by the piezoelectric
device.In second research where a piezoelectric generator
was put to the test and generated some 2,000 watt-hours
of electricity. The setup consists of a ten-meter strip of
asphalt, with generators lying underneath, and batteries
in the road’s proximity. So that it is clear by using parallel
combination we can overcome the problems like of impedance
matching and low power generation. The results
clearly show that piezoelectric materials are the future of
electric power generation.