Slider Dynamics With Adhesive Force in Near-Field Recording

A near-field optical disk drive uses near-field optics to read/write disk data at a flying height of about 50 nm. Effects of interfacial adhesive forces, including van der Waals forces and electrostatic forces, become more evident during ultralow flying. However, the pickup head-flying-height variation is affected by the suspension, disk flutter, and air flow between the flying head and disk. An analysis model consisting of a simplified suspension and an air-bearing model with springs and dampers in three directions (focusing, pitching, and rolling) is used to simulate the dynamic behavior of the flying head. This study proposes an improved method for measuring the slider's flying-height variation. Simulation results with and without interfacial adhesive forces are compared