Energy harvesting and wireless power transmission by a hybridized electromagnetic–triboelectric nanogenerator
Energy harvesting and power delivery are key technologies for self-powered systems towards mobile electronics, the internet of things and sensor networks. A critical issue is not only how to efficiently harvest environmental mechanical energy, but also how we can wirelessly transmit the harvested energy. Here, we have demonstrated a rotating-disk-based hybridized electromagnetic–triboelectric nanogenerator for simultaneously scavenging rotational energy and wirelessly transmitting energy using coils. Under a rotating rate of 900 rpm, the electromagnetic generator (EMG) and triboelectric nanogenerator (TENG) can produce output powers of about 137.39 mW (power density 180 μW g−1) at a matched loading resistance of 300 Ω and 217.8 mW (power density 1152 μW g−1) at a matched loading resistance of 20 kΩ, respectively. Moreover, the output current of the hybridized nanogenerator is increased to about 130 mA for wireless transmission. The power can be wirelessly transmitted up to a distance of ∼60 cm in real time based on helical coils. LEDs can be lighted up. When a supercapacitor bank is applied for storing the generated electricity from the nanogenerator, the wireless transmitted power can charge a mobile phone located at 100 cm away from the transmitter by using a pair of customized helical wire coils. Furthermore, the received output of voltage can reach 153 V at a distance of 80 cm through a commercial voltage booster. The hybridized nanogenerator with wireless power transmission has potential applications in sustainably driving some self-powered and mobile electronic devices particularly for implantable medical devices and the internet of things.