| Abstract |
The development of Internet of Things (IoT) technology has greatly contributed to the development of smart cities, from smart homes to smart factories. The quality of human life is enriched by the comprehensive sensing and seamless communication of IoT devices in different spaces. As a foundation, wireless sensor networks, which currently consist of various fixed sensors, are experiencing sustainability and compatibility issues. Here, we report a broadband vibrational piezoelectric energy harvester (PEH) with frequency up-conversion (FUC) function, consisting of a high-frequency piezoelectric cantilever (HF-PC) with a resonant frequency of 214 Hz and a low-frequency stainless-steel cantilever (LF-SC) with a resonant frequency of 36 Hz, and the HF-PC is fabricated by MEMS PZT thick film technology. Under the excitation of external low-frequency vibration, the LF-SC at the bottom impinges on the HF-PC during its motion, and in this way converts the external low-frequency vibration into high-frequency piezoelectric cantilever vibration. The maximum output power of a single HF-PC is 521.5 : at 214 Hz and 1.0 g acceleration. On the other hand, the FUC-PEH is capable of achieving a maximum voltage output of 26.6 V over a drive frequency range of 26.2 Hz to 48.4 Hz, with an operating bandwidth of 22.2 Hz and a maximum output power of 775.3 μW. The output power is sufficient to power the Bluetooth temperature and humidity sensor, demonstrating the high power output and excellent charging capability of the FUC-PEH. © 2022 IEEE. |
