System design considerations for MEMS-actuated magnetic-probe-based mass storage

This paper presents common system design considerations imposed on magnetic storage devices that employ MEMS devices for positioning of a magnetic probe device over a magnetic media. The paper demonstrates that active servo control of the probe tip to media separation can be achieved with sub-nanometer accuracy. And, it demonstrates that reasonable-size capacitive sensors can resolve probe tip motions with a noise floor of roughly 22 picometers, allowing them to be used as position sensors in magnetic force microscope (MFM) readout approaches. In addition, this paper demonstrates that although MEMS media actuators can achieve scanning ranges of +/- 50 um, the mass of the media sled imposes important access time and data rate constraints on such MEMS-actuated mass storage devices.