Abstract
Piezoelectric vibration energy harvesting technology has attracted significant attention for its applications in integrated circuits, microelectronic devices, and wireless sensors due to high power density, easy integration, simple configuration, and other outstanding features. Among piezoelectric vibration energy harvesting structures, the cantilevered beam is one of the simplest and most commonly used structures. In this work, a vertically staggered rectangle-through-holes (VS-RTH) cantilevered model is proposed, which focuses on the multi-directional vibration collection. To verify the output performance of the device, this paper employs basic materials and fabrication methods with mathematical modeling. The simulations are conducted through finite element methods to discuss the properties of VS-RTH energy harvester on resonant frequency and output characteristics. Besides, an energy storage circuit is adopted as a collection system. It can achieve a maximum voltage of 4.5 V which is responded to the harmonic vibrating input of 1 N force and 1 m/s2 in a single vibrating direction. Moreover, the power density is 2.596 W/cm3 with a 100 kΩ resistor. It is almost four times better than the output of unidirectional cantilever beam with similar resonant frequency and volume. According to the more functionality in the applications, VS-RTH energy harvester can be used in general vibration acquisition of machines and vehicles. Except for electricity storage, the harvester can potentially employ as a sensor to monitor the diversified physical signals for smooth operation and emergence reports. Looking forward, the VS-RTH harvester renders an effective approach toward decomposing the vibration directions in the environment for further complicating vibration applications.
Time-varying output performances of piezoelectric vibration energy harvesting under nonstationary random vibrations
