Study of Micro/Nano Scale Displacement by Electro-Maglev System Using Bulk Superconductors and Permanent Magnet

In order to control the displacement of devices within a micro/nano scale, in this study, an active-magnetic levitation (maglev) system composed of a single-grained Y-Ba-Cu-O high temperature superconductor (HTS) bulk, a rectangular Nd-Fe-B permanent magnet (PM), and a Helmholtz coil was constructed. It is well known that the magnet can be levitated stably above superconductors by the flux trapping effect. By changing the current in the Helmholtz coil, the additional magnetic field was used to adjust the levitation height of the PM. The experimental results show that a D.C. power supply with the sensibility of 10^-2 ampere was able to adjust the levitation height to be accurate within a micrometer (mum) range. An optic-fiber displacement sensor was used to measure the micro/nano scale displacement. The linear relationships between applied current, field cooling height, and non-contact displacement were determined and will be discussed in this report.