Multidirectional Piezoelectric Vibration Energy Harvester Based on Cam Rotor Mechanism

Abstract

The techniques that harvest mechanical energy from low-frequency, multidirectional environmental vibrations have been considered a promising strategy to implement a sustainable power source for wireless sensor networks and the Internet of Things. However, the obvious inconsistency in the output voltage and operating frequency among different directions may bring a hindrance to energy management. To address this issue, this paper reports a cam-rotor-based approach for a multidirectional piezoelectric vibration energy harvester. The cam rotor can transform vertical excitation into a reciprocating circular motion, producing a dynamic centrifugal acceleration to excite the piezoelectric beam. The same beam group is utilized when harvesting vertical and horizontal vibrations. Therefore, the proposed harvester reveals similar characterization in its resonant frequency and output voltage at different working directions. The structure design and modeling, device prototyping and experimental validation are conducted. The results show that the proposed harvester can produce a peak voltage of up to 42.4 V under a 0.2 g acceleration with a favorable power of 0.52 mW, and the resonant frequency for each operating direction is stable at around 3.7 Hz. Practical applications in lighting up LEDs and powering a WSN system demonstrate the promising potential of the proposed approach in capturing energy from ambient vibrations to construct self-powered engineering systems for structural health monitoring, environmental measuring, etc.

Design and experimental investigation of a positive feedback magnetic-coupled piezoelectric energy harvester

“…Most traditional piezoelectric vibration energy capture devices use piezoelectric vibrators with fixed mass blocks at the end as energy exchange components, which are adapted to single vibration direction and narrow effective frequency band, and are difficult to meet the needs of self-power supply in cases of multi-direction vibration and large frequency variation range [17]. Therefore, finding ways to expand the operational frequency range of the energy collector in order to meet the requirements of multi-directional energy capture is a pressing issue within this field.…”