Design of high-performance triboelectric-piezoelectric hybridized mechanical energy harvester inspired by three-phase asynchronous generator

Hybridized nanogenerators harvesting ambient mechanical energy via multiple energy conversion mechanisms is attractive for the development of next-generation energy sources. However, existing devices are still restricted in device size, structure complexity, power circuit and energy utilization scheme. Herein, inspired by the principle of three-phase asynchronous generator, we designed a triboelectric-piezoelectric hybridized mechanical energy harvester (HMEH) that tightly combines triboelectric and piezoelectric components in all-in-one package. Through the strategy of three-phase full-wave rectifier and integration of triboelectric/piezoelectric components with similar impedance to optimize the power extraction, one HMEH device can deliver remarkable outputs of 810 V and 0.65 mA at excitation frequency of 0.5 Hz, and even up to 1.10 mA at 4.0 Hz. The device also can endure 40,000 contact-separation cycles stability tests with no device failure and little outputs decay, demonstrating its excellent durability and reliability. The power density of this HMEH device approaches a high value of 1.02 mW cm−2 among similar contact-separation mode HNGs reported to date. Scalable performance of ∼4 mA can be obtained through the 2 × 2 HMEH arrays, supplying power for a smart band in sensing of heart rate and transmitting data wirelessly. The continuous charging of supercapacitor and lithium battery through HMEH arrays are demonstrated, providing extended energy utilization schemes for pulse-power and constant-power types electronics. This work can provide new insights in designing high-performance hybridized mechanical energy harvester and facilitate the development of power-generating technologies in further real-life applications, such as smart road infrastructures, wearable electronics and large-scale blue energy.