writes "It's possible that in the future that voice conversations on your cell phone could generate enough electrical power to run the phone, without batteries.
That's one possible outcome of recent work by a team of Texas researchers, who appear to have discovered that by building a certain type of piezoelectric material to a specific thickness (about 21 nanometers, compared to a typical human hair of 100,000 nanometers), you can boost its energy production by 100 percent. And the technology could power not just phones, but a whole range of low-power mobile devices and sensors. The breakthrough is an example of "energy harvesting" that can convert one kind of energy, such as vibrations or solar rays, into electricity."Link to Original Source