Hybridized nanogenerator for simultaneously scavenging mechanical and thermal energies by electromagnetic-triboelectric-thermoelectric effects

High-efficiency rotation based energy harvesters require simultaneous scavenging of mechanical energy and rotation-induced wasted thermal energy. A hybridized nanogenerator is reported that has an electromagnetic generator (EMG), a triboelectric nanogenerator (TENG), and a thermoelectric generator (ThEG) for simultaneously harvesting mechanical and thermal energies in one process. As driven by the relative rotation motions between two disks, all of the EMG, TENG and ThEG can deliver outputs due to the cooperative operation of electromagnetic, triboelectric, and thermoelectric effects. With increasing the working time of the hybridized nanogenerator, the output power of EMG can be kept in a stable value, and an obvious increase can be seen for the output power of ThEG, while the output power of TENG exhibited a dramatic decrease. By using the power management circuits, all of the EMG, TENG, and ThEG devices can deliver a constant output voltage of 5 V, where the hybridized nanogenerator can produce a pulsed output current peak of about 160 mA. Moreover, the hybridized nanogenerator has been successfully installed in a commercial bicycle to scavenge biomechanical energy for lighting up globe lights and charging up a cell phone.