Comprehensive Analysis of the Energy Harvesting Performance of a Fe-Ga Based Cantilever Harvester in Free Excitation and Base Excitation Mode

Abstract

Vibration energy harvesting attempts to generate electricity through recycling the discarded vibration energy that is usually lost or dissipated, and represents an alternative to traditional batteries and may even lead to reliable self-powered autonomous electronic devices. Energy harvesting based on magnetostrictive materials, which takes advantage of the coupling characteristics of the Villari effect and the Faraday electromagnetic induction effect, is a recent research field of great interest. Aiming to develop a new type of magnetostrictive energy harvester using Fe-Ga alloy, which is suitable for harvesting the vibration energy from base excitations and free excitations, a Fe-Ga based cantilever harvester was proposed. The energy harvesting performance of the harvester prototype, including its resonance characteristics, open-circuit output voltage-frequency response and amplitude characteristic under base excitation, influence of external resistance, energy harvesting performance under free excitation, the function of pre-magnetization and so on was studied systematically and carefully by experiments. In terms of the volume power density, the harvester prototype without pre-magnetized magnet when in series with the optimal resistor load displays a value of 2.653 mW/cm3. The average conversion efficiency without a pre-magnetic field is about 17.7% when it is in series with a 200 resistance. The energy harvesting and converting capability can therefore be improved greatly once the Fe-Ga beam is highly pre-magnetized. The prototype successfully lit up multi-LEDs and digital display tubes, which validates the sustainable power generation capacity of the fabricated prototype.

Analysis of the Key Factors Affecting the Capability and Optimization for Magnetostrictive Iron-Gallium Alloy Ambient Vibration Harvesters

“…Layouts B4, B5, B5 and B7 are better than B1, B2 and B3. It can be seen that the maximum voltage reaches to 1.52 V (at 6 g acceleration), which also reaches 1.14 V even at moderate acceleration (4 g), which may be also larger than that reported in the literatures [44,48] about MSM vibration harvester to a certain extent. Although the voltage is smaller than that reported in the literature [34] (2 V at 4 g acceleration), the voltage density (voltage divided by the area of active layer) 1.9 V/cm 2 is larger than that of [34] (1.73 V/cm 2 ).…”

“…The function of the bias magnetic field on the initial state of magnetic domain and the Villari effect of MSM is similar to the effect of pre-tightening force on Joule effect. Many references [44,45] have mentioned that the bias magnetic field has an influence on the characteristics of MSM vibration harvesting devices. In most of the reports, the permanent magnet was just arranged directly in a fixed position on the harvester in a fixed form, however, it is not clear which arrangement can maximize the energy conversion capacity.…”

Performance of Fe–Ga alloy rotational vibration energy harvester with centrifugal softening

“…Therefore, energy harvesters based on magnetostrictive materials usually have a small size and relatively light mass, making them highly suitable for integration with other application devices. Compared to piezoelectric materials that present disadvantages such as eother creeping and low sensitivity to mechanical shocks or environmental vibrations [25], magnetostrictive materials can achieve high energy conversion efficiency through the coupling of the Viralli effect and electromagnetic induction [26]. In addition, they provide high power density, high durability, small anisotropy, high processability, and low saturation field, and thus gradually have become robust transduction materials [27,28].…”

Design and analysis of magnetostrictive two-dimensional kinetic energy harvester

“…Existing studies have shown that the bias field setting of a magnetostrictive material directly affects the electrical output of the harvester [41,42]. Adding a bias magnetic field can change the magnitude of the magnetic moment within the magnetostrictive material and induce more magnetic domains to deflect, causing the material to exhibit a stronger magnetization intensity.…”