With increasing storage density of computer rigid disk drives, increased contact and wear at the head disk interface is unavoidable. The flying height of a typical sub-ambient pressure slider is below 20nm, leading to contacts with asperities on the media. These contacts can be effectively investigated using acoustic emission analysis. Acoustic Emission (AE) is a stress wave that is subject to dispersion and reflection. Impact of the slider onto the disk is defined by the occurrence of the slider body ringing frequencies. These modes are greater than 700kHz for nano sliders and greater than 1.2MHz for pico sliders. In this paper, various acoustic emission sensors and piezo-electric crystals are employed to study impacts between slider and disk. Furthermore, the impact is analyzed using laser-Dopplervibrometry (LDV). In addition, the impact of a small spherical ball dropping on the rails of a slider is investigated using finite element analysis.
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