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 pro be device over a magnetic media. The paper demonstrates that active servo c ontrol of the probe tip to media separation can be achieved with sub-nanome ter 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.