Ultra-Low Frequency Eccentric Pendulum-Based Electromagnetic Vibrational Energy Harvester

Abstract

With the development of low-power technology in electronic devices, the wireless sensor network shows great potential in applications in health tracing and ocean monitoring. These scenarios usually contain abundant low-frequency vibration energy, which can be collected through appropriate energy conversion architecture; thus, the common issue of limited battery life in wireless sensor devices could be solved. Traditional energy-converting structures such as the cantilever-beam type or spring-mass type have the problem of high working frequency. In this work, an eccentric pendulum-based electromagnetic vibration energy harvester is designed, analyzed, and verified with the finite element analysis method. The pendulum that contains alternative distributed magnets in the outer side works as a rotor and has the advantages of a simple structure and low center frequency. The structure size is well scalable, and the optimal output performance can be obtained by optimizing the coil thickness and width for a given diameter of the energy harvester. The simulation results show that the energy harvester could work in ultra-low frequencies of 0.2–3.0 Hz. A full-scale prototype of the energy harvester is manufactured and tested. The center working frequency is 2.0 Hz with an average output power of 8.37 mW, which has potential for application in driving low-power wireless sensor nodes.

Vibration Converter with Passive Energy Management for Battery-Less Wireless Sensor Nodes in Predictive Maintenance

“…Energies 2022, 15,1982 16 of 18 of acceleration can be usual in real system operations, and the proposed system shows good sensitivity to the reorganization of the dysfunctionality of the system behavior.…”

“…Until now, in the state of the art, the developed harvesters for such vibration sources have several limitations. In [15], an eccentric pendulum-based electromagnetic converter was developed to harvest energy from 0.1 g acceleration and a frequency of 2 Hz, which was successful, but the total volume of the harvester was 153.9 cm 3 , which results in a bulky system. Further, in [16], a compact solution with a total volume of ~27.4 cm 3 was developed for a low frequency of 10 Hz, but was unable to generate energy under 1 g of applied acceleration.…”

Harvesting Inertial Energy and Powering Wearable Devices: A Review

“…A lower system damping, a greater external excitation, and a greater weight and eccentricity radius of the eccentric mass are all advantageous for entering self‐excited rotation mode. [ 131 ]…”

Overview of Human Kinetic Energy Harvesting and Application

“…Zhou et al 24 conducted theoretical and experimental analyses of stacked magnetic modulation harvesters with frequency upconversion to improve the energy harvesting performance of oscillating motion. Li et al 25 studied the electromagnetic vibration energy harvester of an ultralow frequency eccentric pendulum; the working frequency was 2.0 Hz, and the average output power was 8.37 mW. Slip-type EMGs mostly use oscillation-based power generation methods.…”