Design, fabrication, sensor fusion, and control of a micro X–Y stage media platform for probe-based storage systems

Due to the renowned superparamagnetic effect encountered in conventional magnetic data storage, many alternative futuristic data storage platforms have been proposed, e.g. Probe-Based Storage Systems (PBSS) successfully demonstrated in the “Millipede” project [Eletheriou E, Antonakopoulos T, Binning GK, Cherubini G, Despont M, Dholakia A, et al. Millipede—a MEMS-based scanning-probe data-storage system. IEEE Trans Magn 2003;39(2):938–45]. In this paper, a micro X–Y stage with 6 mm × 6 mm recording media platform actuated by capacitive comb drives is designed and fabricated in a so-called “Nanodrive” PBSS. The developed prototype is fabricated by micromachining techniques with the integration of a 40 nm thick PolyMethyl-MethAcrylate (PMMA) recording media. Using Finite Element Analysis (FEA) on the developed platform, the first two dominant in-plane resonant modes of the micro X–Y stage at 440 Hz are captured. A displacement range of up to 20 μm can be achieved at an input driving voltage of 55 V. A Capacitive Self-Sensing Actuation (CSSA) circuit and robust decoupling control scheme are also designed for the micro X–Y stage for improved servo control.