Surface acoustic wave-based sensing and actuation of contamination

Patent metadata

Field	Value
Publication number	US-11087790-B2
Application number	US-202016814028-A
Country	US
Kind code	B2
Filing date	Mar 10, 2020
Priority date	Apr 18, 2018
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A method includes producing a first surface acoustic wave (SAW) on a magnetic head slider using a first interdigitated transducer (IDT), wherein the SAW has a first set of wave characteristics. The method also includes receiving the first SAW at a second IDT on the magnetic head slider. The method also includes analyzing the SAW for a second set of wave characteristics. The method also includes determining, based on the analyzing, that a substance having at least one characteristic is located in a path of the SAW on the magnetic head slider.

First claim

What is claimed is:

1. A method of determining the presence of a contaminant on a surface of a slider, comprising:
receiving a first surface acoustic wave (SAW) at a transducer on a magnetic head slider;
analyzing the first SAW for one or more wave characteristics; and
determining, based on the analyzing, that a contaminant having at least one characteristic is detected on the magnetic head slider.

2. The method of claim 1 , further comprising:
producing a second SAW using the transducer, wherein the second SAW is configured to actuate the contaminant based on the at least one characteristic of the contaminant.

3. The method of claim 1 , wherein the one or more wave characteristics comprise a first set of wave characteristics that include: a first amplitude, a first velocity, a first wavelength, a first phase, and a first direction of propagation.

4. The method of claim 2 , wherein the second SAW comprises a second set of one or more wave characteristics that include: a time delay, a second amplitude, a second velocity, a second wavelength, a second phase, and a second direction of propagation.

5. The method of claim 2 , wherein the first SAW is used for sensing the contaminant, and the second SAW is used for actuating the contaminant.

6. The method of claim 1 , wherein the first SAW is produced on a trailing edge of the magnetic head slider.

7. A head slider apparatus for use in a hard-disk drive, comprising:
a magnetic head slider comprising a first surface, wherein a first transducer and a second transducer are located on the first surface;
a controller in communication with the first transducer and the second transducer;
wherein the first transducer is configured to create a first surface acoustic wave (SAW) having a first set of wave characteristics;
wherein the second transducer is configured to receive the first SAW created by the first transducer, the received first SAW having a second set of wave characteristics; and
wherein the controller is configured to analyze the received first SAW by comparing the second set of wave characteristics to the first set of wave characteristics.

8. The head slider apparatus of claim 7 , wherein if the controller determines that a contaminant is located on the first surface, then the controller is configured to cause the first transducer create a second SAW, and wherein the second SAW is configured to actuate the contaminant.

9. The head slider apparatus of claim 8 , wherein the second SAW is configured to actuate the contaminant by having a contact angle and power at a time of SAW incidence with the contaminant.

10. The head slider apparatus of claim 7 , further comprising:
an acoustic reflector configured to reflect the first SAW from the first transducer to the second transducer.

11. The head slider apparatus of claim 7 , wherein the first transducer and the second transducer are the same transducer.

12. A method for actuating a substance on a magnetic head slider, comprising:
receiving a first set of wave characteristics;
determining, based on the first set of wave characteristics, that a substance having at least one characteristic is located on a surface of the magnetic head slider; and
producing a first wave on the surface of the magnetic head slider using a first transducer, based on the first set of wave characteristics.

13. The method of claim 12 , wherein the first set of wave characteristics is received at the first transducer.

14. The method of claim 12 , wherein the first wave has a second set of wave characteristics, and wherein the first wave is used for actuating the sub stance.

15. The method of claim 12 , wherein a second wave comprises the first set of wave characteristics, and wherein the second wave is used for sensing the substance.

16. The method of claim 12 , wherein the first set of wave characteristics includes: a first amplitude, a first velocity, a first wavelength, a first phase, and a first direction of propagation.

17. The method of claim 12 , wherein the first wave is a surface acoustic wave (SAW).

18. The method of claim 12 , wherein the first wave on the surface of the magnetic head slider is produced such that the substance is actuated.

19. The method of claim 14 , wherein the second set of wave characteristics includes: a time delay, a second amplitude, a second velocity, a second wavelength, a second phase, and a second direction of propagation.

Assignees

• Seagate Technology Llc

Inventors

• Ramakrishnan Narayanan

Classifications

• G11B5/6058 Primary

  using piezoelectric means · CPC title

• G11B5/6082

  Design of the air bearing surface · CPC title

• G11B5/6076 Primary

  Detecting head-disk contact · CPC title

• H02N2/08

  using travelling waves {, i.e. Rayleigh surface waves} · CPC title