POWERleap!

I was interested in finding new, modern sources of alternative energy. After a quick search, I stumbled upon a concept called POWERleap. POWERleap is a flooring system that converts wasted energy from human foot traffic into electricity. The system uses piezoelectric technology and advanced circuitry design to convert the energy from footsteps into electric energy. The product will be among the first of its kind to take advantage of the unique properties of piezoelectric materials to actually produce usable amounts of electricity.
Besides transferring our wasted energy, how exactly does this alternative energy source work? Well, in simpler terms the product measures pressure, acceleration, strain or force by converting them to an electrical signal. Then, the energy harvesting components are housed in a flooring product that can be custom designed to suit specific applications.
In using piezoelectric technology, the energy source has an extremely high natural frequency and an excellent linearity over a wide amplitude range. Piezoelectricity is a naturally occurring occurrence exhibited by certain materials that generate an electric field when distorted. These materials range from crystals to ceramics and even some polymers, and in these materials, when no force is applied, the atomic structure is in equilibrium and there is no net electric charge. However, when a force is applied, an electric incline is created which generates a voltage across the material. When the material is integrated into a circuit, this voltage will create a DC current. The great advantage of piezoelectric technology is that it is insensitive to electromagnetic fields and radiation, enabling measurements under harsh conditions.
After learning how the product works, I wondered how much electricity the POWERleap could actually produce. According to POWERleap.net, the energy source can generate between 1-5 Watt hours per square foot, depending on the foot traffic volume. Over a 100 meter stretch of sidewalk in daily city traffic, pedestrians can generate around 1 kW of electricity each hour. That’s a lot of energy!
Not only is this particular energy source effective but the electricity generated from this product can be used on a wide variety of applications that meet client needs and create a closed loop system. The energy source can be installed into city sidewalks, public parks, university campuses, and in corporate campuses. It can be put into more entertainment- like atmospheres such as dance clubs, gyms and fitness clubs, sports stadiums, and retail chains as well. In the near future, we could be walking down the sidewalks of Chicago and be creating a new form of alternative energy on-site for immediate use.
The only problem with POWERleap and using piezoelectricity is that this type of technology cannot be used for true static measurements. A static force will result in a fixed amount of charges on the piezoelectric material. Working with conventional readout electronics, imperfect insulating materials, and reduction in internal sensor resistance will result in a constant loss of electrons, and yield a decreasing signal. Another problem concerning piezoelectricity is that elevated temperatures cause an additional drop in internal resistance(concept that helps model the electrical consequences of the complex chemical reactions inside a battery). This means that at higher temperatures only piezoelectric materials that maintain a high internal resistance can be used.

http://powerleap.net/index.html
http://en.wikipedia.org/wiki/Piezoelectric_sensor
http://www.electronics-manufacturers.com/products/sensors-transducers-detectors/piezoelectric-sensor/