A measurement of sliding resistance forces for various heads and disks by high-rigidity force sensor

The force on a head/disk interface has been measured using a novel multiaxis force sensor. The sensor has high resonance frequency (about 3 kHz) and high rigidity (about 1 N/μm) and can measure the sliding resistance force, F, accurately. The value of F for various heads and disks at various disk velocities (V) and its changes under repeated contact start-stop (CSS) are measured. Four components of F are identified. It is found that regardless of disk lubricant and head load, F/V is uniquely determined by disk roughness and head-fly-height. As CSS times increase, F becomes larger, and the head takes off at lower head-fly-height because the disk surface becomes smoother