The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Patent No.:

US 8728825 B1

PDF
Full Text
Expired
Date of Patent:
May. 20, 2014

Filed:

Mar. 12, 2012
Applicants:

Po-kang Wang, San Jose, CA (US);

Xizeng Shi, Fremont, CA (US);

Chyu-jiuh Torng, Fremont, CA (US);

Inventors:

Po-Kang Wang, San Jose, CA (US);

Xizeng Shi, Fremont, CA (US);

Chyu-Jiuh Torng, Fremont, CA (US);

Assignee:

Headway Technologies, Inc., Milpitas, CA (US);

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01N 27/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A GMR sensor stripe provides a sensitive mechanism for detecting the presence of magnetized particles bonded to biological molecules that are affixed to a substrate. The adverse effect of hysteresis on the maintenance of a stable bias point for the magnetic moment of the sensor stripe free layer is eliminated by a combination of biasing the sensor stripe along its longitudinal direction rather than the usual transverse direction and by using the overcoat stress and magnetostriction of magnetic layers to create a compensatory transverse magnetic anisotropy. By connecting the stripes in an array and making the spaces between the stripes narrower than the dimension of the magnetized particle and by making the width of the stripes equal to the dimension of the particle, the sensitivity of the sensor array is enhanced.


Find Patent Forward Citations

Loading…