MINIATURE VIBRATION SHAKER FOR MEMS-SCALE VIBRATION-BASED ENERGY HARVESTERS APPLICATION

This paper describes the design and fabrication of miniature electromagnetic-type vibration shaker for generating sinusoidal vibrations. Conventional machining is used to produce different parts of the vibration shaker. The shaker’s table is supported by zig-zag planar beams and a copper wound coil is contained at the lower portion of the shaker’s table. Alternating magnetic field of the wound coil and the magnetic field of the permanent magnet generates a sinusoidal force that causes the shaker’s table to vibrate at the frequency of input electrical signal to the shaker. Modal analysis of the suspension system performed in COMSOL Multiphysics®, indicates that in the first mode of the vibration the shaker’s table is perfectly moving up and down. The developed vibration shaker is characterized for sinusoidal electrical input signal. At different gain levels of the power amplifier, the shaker is subjected to a frequency sweep from 1 Hz to 1 kHz. At resonant frequency of 60 Hz, acceleration amplitudes of 5, 10, 18, 20 g are produced at gain levels of -60, -55, -50 and -48 dB respectively. Beyond 200 Hz almost constant acceleration levels of 1.8, 1.3, 0.9 and 0.7 g are obtained at -48, -50, -55 and -60 dB respectively. Current drawn and power delivered are maximum, when the shaker is operated at the resonant frequency. Operating on the resonant frequency of 60 Hz, a maximum power of 0.6 W is delivered to the shaker at -48 dB gain level.