Modeling, design and analysis of a micro flying slider in near-field optical storage system

Abstract

A micro flying slider is developed to satisfy the demands for large capacity, high data density, and fast transfer rate of mass storage systems. The air-bearing surface of the micro flying slider is designed based on micro fluid theory of hydrodynamics to obtain positive and negative pressures, thereby enhancing flying height stability. The lubrication model is investigated based on the generalized Reynolds equation. The finite volume method is utilized to solve the revised Reynolds equation that governs the air-bearing pressure and flying system behavior. The dynamic model for the slider–disk interface of the micro flying slider is developed, and the air-bearing system is modeled as a 3-degrees-of-freedom, lumped-parameter model to simulate flying characteristics. The air-bearing pressures with flying attitudes in the loading/unloading processes are characterized and calculated using the proposed model, with flying height and pitch angle as the key variables. The sample data obtained via accurate triggering and superposed averaging are processed to acquire modal frequencies and damping ratios based on the parameter identification method of modal analysis technique. System experiments are presented to illustrate the effectiveness of the proposed micro flying slider and its dynamic model for flying-height control. Theoretical analysis and experimental results show that a stable storage working process can be obtained at 1600 rpm and a pitch angle of 1.5°. Moreover, the micro flying slider exhibits satisfactory flying stability, with a near-field working distance of less than 75 nm. Good correlation between the experimental and simulation results is achieved.