An increasing demand for power sources accessible everywhere and at anytime led to the development of harvesting technologies to convert directly mechanical energy from the surrounding environment into electrical energy. A huge step forward in this field arrive in 2006 with the invention of nanogenerators (NG). These devices can convert mechanical energy into electrical one, generating power of the order of some milliwatts. This low level, with the development of modern devices, is enough to directly supply some simple devices or to store energy into capacitors. The most promising type of nanogenerators is based on triboelectric effect. Triboelectric NGs can transform any type of mechanical movement into electrical energy utilizing the mutual movement of two materials.