In this chapter, an energy harvesting platform based on high-permeability material was theoretically studied and tested. Two generations of devices were designed. The first generation consisted of a high-p cantilever vibration energy harvester incorporated a vibrating high-permeability cantilever, a solenoid, and a bias magnet pair. Interaction between the high-permeability magnetic beam and the bias magnets […]

Compared to the previous vibration energy harvester design based on a vibrating high-p beam and a stationary bias hard magnet pair, this new generation device utilizes a vibrating hard magnet pair and a stationary solenoid pair with thick multilayer high-p core materials. The multilayer high-permeability solenoids core leads to significantly increased flux change in the […]

Figure 18.14 shows the measured open circuit voltage of the energy harvester with different springs and resonant frequencies. For spring #1, with resonant frequency of 27 Hz, the peak voltage is 1.18 V for an acceleration amplitude of 2 x g; for spring #2, with resonant frequency of 33 Hz, the generated maximum voltage is […]

The mass of the hard magnet pair, the stiffness of the supporting spring, and the magnetostatic coupling between the solenoids and the hard magnet pair determine the resonant vibration frequency and the output voltage of the energy harvester. The equivalent spring-mass system becomes a nonlinear oscillation system due to the magnetostatic coupling between the solenoids […]

18.3.1 Prototype and Testing Platform The schematic design of the high output power energy harvester is shown in Fig. 18.12. Two identical solenoids with high-permeability/insulator multilayer cores were placed on two sides of a vibrating hard magnet pair with antiparallel magnetization. The key components of this energy harvester are the two identical solenoids with a […]

Table 18.1 shows the figures of merit for vibrating energy harvesters with dif­ferent types of working mechanisms and materials, including magnetoelectric, electrostatic, piezoelectric, magnetoelectric sensor based, magnetostrictive, and high-permeability material-based devices. Among all these different mechanisms, the wide bandwidth energy harvester based on the magnetic coupling between the high-|x material and the bias field of […]

From Fig. 18.10, it can be seen that the working bandwidth is about 10 Hz, 18.5% of the central frequency, compared with 2.1 Hz (Ferro Solution VEH360) or 3.5% of the central frequency, for a typical linear oscillator harvester. The major reason for the large bandwidth is that the magnetic coupling is not linear to […]

Figure 18.8 shows calculated and measured results of the open circuit voltage in two cases. When the magnet pair is set to have antiparallel magnetization, the energy harvester shows a high open circuit voltage with a peak value of 544 mV at a vibration frequency of 54 Hz and an acceleration amplitude of 0.57 x […]