A highly sensitive magnetic configuration-based triboelectric nanogenerator for multidirectional vibration energy harvesting and self-powered environmental monitoring

Vibration energy, which is ubiquitous but usually abandoned energy, has been considered as a promising source of energy to be harvested for future power supply to electronics. In this study, we demonstrate the triboelectric nanogenerator (TENG) with a rationally designed bi-axial vibration responsive magnetic configuration (BVMC). Oblique placement of two magnets enables the system to be bi-axially sensitive and the superior response of such BVMC to vibrations is explored for further utilized to harvest multidirectional vibration energy in a single device. Energy harvesting performance of the multidirectional vibration stimuli-responsive TENG, called MS-TENG, under various vibration conditions is investigated. In addition, the further development of the MS-TENG with an additional magnet exhibits the full (three-dimensional) vibration energy harvesting ability. The MS-TENG is applied under-the-hood of an automobile where typically abandoned vibrations occur frequently. Turning on the engine on the ignition enables the arrayed MS-TENG to generate a stable output just by engine trembling. Furthermore, the normal human motion-driven vibration is used to charge the commercial capacitor to wirelessly transmit the signal including information of ambient temperature and humidity from the Bluetooth thermo-hygrometer sensor. Consequently, the present TENG with simple but bi-axially sensitive magnetic configuration has a great potential to effectively harvest the multidirectional and low-frequency vibrations around us for future feasible applications.