A full-packaged rolling triboelectric-electromagnetic hybrid nanogenerator for energy harvesting and building up self-powered wireless systems

The newly invented triboelectric nanogenerator (TENG) shows a significant potential to be a powerful technology for converting mechanical energy into electricity as a complementary usage for solving our future energy demanded for micro- and macro- grid. However, packaging and robustness are critical factors for TENG toward practical applications since the performance of TENG is affected by environmental conditions such as humidity. Here, a full-packaged waterwheel-like rolling triboelectric-electromagnetic hybrid nanogenerator (TEHNG) for harvesting mechanical energy in harsh environment has designed. The integrated silicone rubber-magnet rods and electrodes laminated by a layer of nylon film, which worked as the triboelectric material, are used to fabricate a rolling friction free-standing triboelectric layer mode triboelectric nanogenerator (RFS-TENG) and combining with copper coils subtly, electromagnetic generator (EMG) is achieved. The rolling friction causes almost no damage to the triboelectric layers and there is no obvious normalized current decay found after 3-days continuous working at 0.5 Hz. Thus, this novel design makes the TEHNG easier to be packaged, and prevent from water interference revealing a superior robustness. It is also found that the developed TEHNG broadens the working frequency range as TENG can work more effectively for converting the mechanical energy at lower-frequencies less than 5 Hz energy scavenging while EMG can work much better at higher-frequencies above 5 Hz. Moreover, combining with hand shaking and water wheel, the device can be demonstrated to collect the energy of handy and water-flow flexibly. Furthermore, using current output signals of the EMG, a self-powered wireless frequency and revolution sensor systems are also demonstrated. This work presents a new platform of hybrid generator for harvesting mechanical energy in harsh environments with several desirable features such as the broadened frequency bands, better portability and for building up self-powered wireless sensor systems.