Combination of Magnetostrictive/ Piezoelectric Materials Composite and Electromagnet for Zero Power Levitation

This paper presents zero-power levitation using a composite of magnetostrictive (GMM) /piezoelectric (PZT) materials. The control of the magnetic force is based on the inverse magnetostrictive effect of the GMM, by which the magnetic force can be varied with applied voltage onthe PZT. The distinctive advantage of the composite is zero power consumption while maintaining a constantmagnetic force due to the capacitive property of the PZT. So far we have succeeded the magnetic levitation and verified the advantage of zero power in stationary state. The robustness is, however, low dueto the limited variation of the magnetic force. In this paper, we propose the combination of the composite and electromagnet, where the bias gap is adjusted by the composite and the motion of the levitated yoke is stabilized by the electromagnet. The experimental results of step response verified the zero power consumption in both devices and that the composite driven by small DC-DC converter functions sufficiently to adjust the bias gap.