Wahad Ur Rahman, Farid Ullah Khan
This article introduces a novel hybrid flow energy harvester that combines electromagnetic and piezoelectric transduction methods to capture the kinetic energy of a fluid flowing through a pipeline. A key innovation of this study is the introduction of a proof mass with a sharp central protrusion placed on the piezoelectric plate. This design lowers the natural frequency of the device, thereby increasing the plate deflection and significantly enhancing the power generation under realistic flow conditions. The effect of this structural modification was validated through COMSOL Multiphysics simulations, which confirmed the improved dynamic response. At a flow pressure of 2.90 kPa, flow rate of 11.08 l/s, and flow frequency of 304 Hz, the developed harvester demonstrated optimum performance by delivering a combined AC power output of 366 µW and DC power of 156 µW. This harvested energy was sufficient to charge a 4.8 V rechargeable battery unit from 0.81 to 4.09 V within six hours. Furthermore, a comprehensive comparative analysis was conducted, benchmarking the proposed harvester against recent state-of-the-art devices in terms of size, output power, and power density. The results demonstrate that the developed harvester outperforms most reported designs of a similar scale, offering a higher normalised power output.