Inductance enhancement of a MEMS inductor with self-aligned magnetic nanoparticles

This paper reports a novel method of integrating magnetic nanoparticles (MNPs) with a MEMS inductor. The proposed method is based on the self-alignment of MNPs in response to a magnetic field generated by the integrated MEMS inductor itself. Because it is the natural tendency of MNPs to gravitate towards spots of maximum magnetic flux density, the alignment process results in an MNP distribution that is optimal for maximizing inductance. This new method of increasing the inductance of a MEMS inductor has been first suggested and demonstrated here. With only a 1wt% MNP mixture and a simple planar spiral inductor structure, the proposed method yielded a significant inductance gain of over 50%, which is comparable to the state of the art inductance gain achieved with MNPs by any method. In previous reports, this much gain was obtained with a 50wt% MNP mixture.