Simulation and analysis of electromagnetic in-plane microgenerator

This study focuses on the design, simulation, fabrication, and test of the in-plane microgenerator to obtain a high-power output. The microgenerator comprises multilayer planar silver (Ag) microcoil of lowtemperature cofired ceramics (LTCC) and multipole hard magnet of Nd/Fe/B (neodymium, iron, and boron). The LTCC process is an approach that saves costs and time to fabricate the microcoil. The multipole hard magnet of Nd/Fe/B provides the large magnetic energy product to contribute to the power. Finite element simulations have been carried out using COMSOL Multiphysics® to observe electromagnetic information. The induced voltages of coils in different basic geometric shapes, including square-shaped coils, circle-shaped coils, and sector-shaped coils, are simulated separately in this study. A prototype of the microgenerator is <1 cm³ in volume size. The simulated result can be compared to the experimental one. The results of simulation reveal that this microgenerator with a sector-shaped microcoil generates a maximum effective value of the induced voltage of 232.7 mV and the power of 2.5 mW. And the 1-μm gap between the microcoil and the magnet achieved is the value that is mentioned above. Experimental measurement shows close agreement with finite element simulations.