An vibration energy harvester with broadband and frequency-doubling characteristics based on rotary pendulums

• A broadband magnetoelectric vibration energy harvester using rotary pendulums.
• The proposed harvester has broadband and frequency-doubling characteristics.
• An analytical model is developed to analyze the nonlinear vibration, the frequency and electrical-output characteristics of the harvester.
• Load power of 970.2 μW was achieved at a frequency of 14.8 Hz and 0.5 g acceleration.

This paper describes a vibration energy harvester with broadband and frequency-doubling characteristics based on rotary pendulums. The harvester is composed of a Terfenol-D/PMN-PT/Terfenol-D magnetoelectric transducer and a rotary pendulum embedded with six magnets. An analytical model is developed to analyze the nonlinear vibration, the frequency response and electrical-output characteristics of the harvester. A prototype is fabricated and tested. The experimental results are in agreement with the analytical results. The results show that the harvester has broadband and frequency-doubling characteristics and can produce high output power at low frequency. The prototype has a 3 db bandwidth of 3.2 Hz and an output power of 970.2 μW at 0.5 g (1 g = 9.8 m/s2) RMS acceleration with a resonant frequency of 14.8 Hz.