06-12-2012, 05:35 PM
THE POWER BENEATH YOUR FEET
THE POWER BENEATH YOUR FEET.doc (Size: 401.5 KB / Downloads: 33)
Abstract—
In this era of increasing energy costs and decreasing supplies of fossil fuels, emphasis on protecting the environment and creating sustainable forms of power have become vital, high priority projects for modern society. It is imperative that clean, renewable sources of energy be put into practice if we are to wean ourselves off of more traditional sources of power such as fossil fuels. Currently, there is a need to utilize alternative forms of energy. Cleaner, more sustainable forms of electrical power are needed in order to keep costs lower and to insure a healthier environment for future generations. Much energy harvesting research has been conducted with ceramic based piezoelectric transducers on account of their relatively large electrical response to mechanical excitation. However, notwithstanding their comparatively low piezoelectric coefficients, piezoelectric polymers too hold promise as energy harvesting materials due to their flexibility and strength which make them ideal candidates for use in more diverse applications. Yet in order to generate appreciable power, these polymers must be utilized in the most efficient manner possible. Taking these factors into consideration, a research on how this method of energy harvesting can be utilized in colleges and universities is done and examined.
INTRODUCTION
Adequate availability of inexpensive energy is the most important requirement to heal the energy crisis. Over the last decade, green ideas, awareness campaigns, subsidies have been given by the policy makers and industrialists to help build the concept of using nonconventional sources of energy. However, the feasibility of using these methods in a poverty-stricken country like India has always been the burning question among critics. This has paved way for Scientists to invent new, ingenious ways of helping the world come out of this crisis.
Among one of the more recent Sciences that were discovered is Piezoelectricity which has been derived from the concept of energy harvesting.
Energy harvesting, or energy scavenging, is a process that captures small amounts of energy that would otherwise be lost as heat, light, sound, vibration or movement. Energy harvesting devices converting ambient energy into electrical energy have attracted much interest in both the military and commercial sectors. Some systems convert motion, such as that of ocean waves, into electricity to be used by oceanographic monitoring sensors for autonomous operation. The problem with energy harvesting is that it provides very small amount of power for low- energy electronics.
WORKING PRINCIPLE
There are two types of piezoelectric materials; piezoelectric ceramics and single crystal materials. The former has high sensitivity which degrades over time.The less sensitive 'natural' single crystal materials (gallium phosphate, quartz, and tourmaline) have much higher, almost infinite – long term stability. There are also new single crystal materials commercially available such as Lead Magnesium Niobate-Lead Titanate (PMN-PT).
Piezoelectric materials can work in 2 modes depending on the way the force is being applied to the material.
1. A lateral force is applied in the direction perpendicular to the polarization direction, an example of which is a bending beam that has electrodes on its top and bottom surface.
2. Force applied is in the same direction as the polarization direction, an example of which is a bending beam that has all electrodes on its top surfaces.
. FUTURE SCOPE
Efforts are afoot internationally to incorporate piezoelectricity into the clean energy mainstream. While state-of-the art uses of this electricity-generating technology have debuted in countries such as England, the Netherlands, Japan, and Israel, the U.S. is currently running at the back of the pack of global leaders in this space. News about scientific breakthroughs enabling piezoelectric devices to be incorporated as sustainable building materials has not yet percolated to Americans' mainstream awareness level. This needs to change. Wide scale employment of piezoelectric power as an energy source is no longer merely a conceptual notion fit to appear in science fiction novels.
Revolutionary developments in piezoelectric technology now permit the kinetic energy generated from people walking and dancing, as well as from moving vehicles, to be converted into clean power. Innovative devices employing piezoelectricity offer vast public benefits and potential business opportunities in both the long and short terms. Increased piezoelectricity usage could be a trend that plays a significant role in shaping tomorrow's world in the alternative energy sector as well as in financial markets