A new type of Acoustic Emission sensor using a thin film piezoelectric material (sputtered ZnO) was developed for measuring head-disk interaction in a rigid magnetic disk system. The sensor is mounted on a Si slider (length: 3 mm) and was fabricated using micro-machining techniques in our on-going efforts to downsize sliders. Some fundamental tests of the sensor were conducted: sensitivity and frequency characteristics, and a flying test over a rotating bump disk.
Imai, S., Tokuyama, M., Hirose, S., Burger, G. J., Lammerink, T. S. J., & Fluitman, J. H. J. (1995). Thin-film piezoelectric impact sensor array fabricated on a Si slider for measuring head-disk interaction. IEEE transactions on magnetics, 31(6), 3009-3011. [10.1109/20.490253]. https://doi.org/10.1109/20.490253