Effect of Intermolecular Forces on the Dynamic Response of a Slider

As the spacing between the slider and the disk approaches atomic distances, near range intermolecular forces start to act at the slider-disk interface. Wu and Bogy have numerically predicted that intermolecular forces become of importance when the slider-disk spacing is lower than 5nm [1]. Thornton and Bogy have proposed that it may not be possible for a slider to fly at a very low flying height without “snapping” and without having slider disk contacts [2; 3]. According to their calculations, a slider would “snap” (get pulled very close) to the disk surface, as a result of attractive intermolecular forces, when the flying height is lowered below a certain “critical” flying height. However, the question arises whether a slider is likely to “snap” at flying heights greater than the “critical” flying height due to its dynamic response.