Electric power from mechanical stress Energy Harvesting. Piezoelectric nanofibers fabrics . Imagine to enter a Mall where the floor has been paved with this fabric and by your walking to power led lighting. Imagine to wear your gym suit and recharge your device while jogging or running or working out, or monitoring your heart rate and your life parameters. Imagine to make sensors or beacons perpetual devices. imagine to monitor architectural structures or frameworks... imagine real smart cities, smart roads, smart stores, with low costs for setting. Imagine.