Analyses of electromagnetic vibration-based generators fabricated with LTCC multilayer and silver spring-inducer

A helical spring-inducer with silver multilayer coils of a low temperature co-fire ceramic (LTCC) technology is firstly developed in this paper for an electromagnetic vibration-based meso-generator. The LTCC process integrates a 7-layer silver micro-coil into a ceramic micro-spring, which provides the potential to enhance current output because of the more compact induction coil. The generator is combined with the spring-inducer and a spacer that are made of two magnets. The device is approximately 0.58 cm3 in volume. Through coupling activity between kinematics and electromagnetism, mechanical energy is converted to electric energy in the system. There is a maximum voltage output of 52.5 mV, a maximum power output of 2.54 mW, a power density of 4.37 mW/cm3 and a normalized power density of 12.07 mW/cm3 g2 (g = 9.8 m/s2) at 71.5-Hz with a 0.03-mm vibration amplitude. In addition, appropriate formulas are derived to analyze the magnetic field, the vibration spring constant and the parasitical damping coefficient for the predicted power outputs. Moreover, the analytical result follows the measured trend; the deviation is 3.9% error for voltage output and 9.7% error for power output. At last, the LTCC fabrication in the meso-generator is validated, and the modeling is feasible.