Identification of the Spectrum Signature of Air-Bearing Slider Dynamics

Characterization of the motion of air-bearing slider with sub-10-nm clearance is becoming a critical aspect of developing advanced head–disk interfaces (HDI) in hard disk drives to achieve higher areal data densities. In this article, the response of sub-10-nm clearance air-bearing slider induced by a bump contact is recorded using laser Doppler vibrometer (LDV). To identify system dynamics in terms of spectral decomposition, the slider response is studied using FFT, power spectrum density, spectrogram, and Hilbert instantaneous spectrum analysis. The results demonstrate that the response of air-bearing slider in instantaneous contact exhibits nonstationary and nonlinear properties which can be accurately identified using Hilbert instantaneous spectrum. The interpretation and spectrum identification based on Fourier analysis and its extension in time–frequency domain could lead to inaccurate results due to their limitation in resolution and linearity assumption.