Self-powered stepped iron-cobalt-vanadium alloy composite structures for long-term seismic monitoring

As an excellent vibration energy harvesting material, iron-cobalt-vanadium alloy can be applied in seismic vibration monitoring. In this paper, a self-powered stepped composite structure based on iron-cobalt-vanadium alloy for long-term seismic monitoring is proposed, which can convert the mechanical energy generated by low-frequency transient seismic vibration into a voltage signal for self-powered monitoring. On the basis of its mechanical analysis, a mechano-magneto-electric coupling model is established. The relation between the performance of the voltage and the performance of the material is derived, a variety of magnetostrictive composite structures are produced, the properties of the materials used and the voltage performance generated by the structures are compared and analysed, and a simulated earthquakes platform is constructed for experimenting, and the maximum voltage is 620 mV under a transient force of 1 N, which proves that the composite structure of iron-cobalt-vanadium alloy is excellent in terms of voltage output. Finite element simulation is also used to analyse the role of generated magnetic field on the voltage output of the structure under different bias magnet arrangements, and the sensor is further optimised. Simulated seismic experiments were then carried out to analyse the voltage characteristics and energy harvesting capability. Experimentally, it was confirmed that the generated voltage and deflection were linear with R2 = 0.9966, and the fitting results are accurate. The structure produces a voltage of 1280 mV, an output power of 14.13 mW and a maximum power density of 139.55 mW cm-3 under a transient force of 2 N. The sensor has the advantages of simple structure, large output signal, easy fabrication and long-term operation, therefore, this work highlights the feasibility of harvesting energy from seismic vibration for long term monitoring. It can have good prospective applications in the domain of developing self-powered seismic monitoring and transient vibration energy harvesting.