Nearmiss Count Between Flying Head and Magnetic Disk by Detecting Electrical Potential of Voltage-Applied Slider

A simple in-situ measurement of flying head dynamics is developed, making use of weak conductive sliders and media as capacitance and resistance sensors. This method is confirmed to detect such abnormal functioning occurring in the head-medium interface as nearmiss, contact or crash. Flying head dynamics are quantitatively studied, using a simple and effective method wherein the slider is excited by externally pressurized air flow. Without this disturbance, the nearmiss count is almost zero, with the number tending to increase up to a resonant frequency governed by the slider inertia and air film stiffness with increasing disturbance, presenting a maximum value at a disk velocity of 3 to 5 m/s.