[citation][nom]house70[/nom]Everybody keeps talking about it as if you can take, say, 20W of walking power and use whatever percentage of it to convert to electricity. If one person burns 20W of energy to walk a certain distance, you will need additional energy to power up whatever it is you need to power up. Remember, those 20W were REQUIRED to do that amount of walking, and muscles will generate heat in the process, no matter what. The ONLY way you could make this work out of those 20W would be to capture and convert the heat (as a by-product of powering the motion) to electricity. because our bodies have a very good temperature homeostasis (look it up), we don't burn somebody if they tough us after a walk, the heat is dissipated by our entire body, not only our legs. That footwear device would be not converting or capturing the heat-dissipated energy, will just make walking a bit harder to generate the extra energy ,because:- one will have to burn the 20W of power to walk PLUS some wattage to power up the devices. There is no way around it (look up thermodynamics). Any device that does that will inherently make walking harder to provide the extra energy (plus the losses in converting process).[/citation]
They are not talking about the heat energy created and used by our body. They are talking about grabbing the kinetic energy created by our movement. Every time you step, there is a force exerted on the sole of each foot. The heat energy they are referring to is the friction that is generated by your foot coming in contact with the ground.
"the two researchers describe a new approach of using kinetic energy to charge batteries"
"What has been lacking is a mechanical-to-electrical energy conversion technology that would work well for this type of application,"