Browse Prior Art Database

Optimized Piezoelectric Sensors for Measuring DASD Head-Disk Interaction

IP.com Disclosure Number: IPCOM000106455D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 78K

Publishing Venue

IBM

Related People

Lee, CK: AUTHOR [+3]

Abstract

While prior art already covers general use of PZT on sliders to detect slider disk contacts (Yeack-Scranton patent, published articles by IBM Berkeley, MIT), it does not cover PZT shape optimization. The various slider vibration modes give different PZT response during slider/disk contact. For a specific slider vibration mode of interest, one can optimize the PZT design to give improve response.

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Optimized Piezoelectric Sensors for Measuring DASD Head-Disk Interaction

      While prior art already covers general use of PZT on sliders to
detect slider disk contacts (Yeack-Scranton patent, published
articles by IBM Berkeley, MIT), it does not cover PZT shape
optimization.  The various slider vibration modes give different PZT
response during slider/disk contact.  For a specific slider vibration
mode of interest, one can optimize the PZT design to give improve
response.

      Disclosed is a procedure for optimizing the performance of
slider-mounted piezoelectric sensors used to detect asperities and to
quantify roughness on magnetic recording disk surfaces.  Slider
contact with disk asperities gives rise to a piezoelectric signal
that is due to the rigid body motion of the slider as well as to the
slider flexural vibration modes [1].  The peak amplitude in the
piezoelectric sensor signal frequency spectrum resulting from the
slider vibration modes is one of the most sensitive means of
detecting slider-disk contact.  Significant improvements in signal to
noise ratio and dynamic range of slider-mounted piezoelectric sensor
[2]  to increase sensitivity to the slider vibration modes.  The
closed-circuit change response of a piezoelectric sensor q is
determined by the piezoelectric constant of the material d and the
in-plane stress field in the piezoelectric slab.  For axial symmetric
piezoelectric materials such as PZT (lead zirconate titanate) and VF
sub 2 VF sub 3 (poly-vinylidene fluoride copolymer), the
closed-circuit charge response can be obtained by

                         q = d integral(sigma sub x + sigma sub y)d
Alpha

(1)
where A is the area covered by both the surface e...