| 摘要 |
A magnetic rotation sensor (20) comprises a first sensing layer (22) (which may comprise a magnetic nanowire (10)) within which a domain wall (12) separates regions of different magnetic orientation (ML, MR), the location of the domain wall being arranged to change when a magnetic field (H) rotates relative to the layer (22), and electronic measuring means arranged to measure the location of the domain wall (12, 42) electronically, and wherein the amount of relative rotation between the sensor (20) and the magnetic field (H) can be determined from the location of the domain wall (12, 42). The domain wall (12, 42) may be created at a nucleation zone in the form of an injection pad (36). The electronic measuring may comprise measuring resistance between electrical contacts (40, 42); the anisotropic magnetoresistance (AMR) will increase with the presence of more domain walls (12, 42) in the first, second, third and fourth portions (24, 26, 28, 30) of the first sensing layer (22). Movement of a domain wall (12, 42) over four portions (24, 26, 28, 30) corresponds to one complete turn of relative rotation (360{) of the magnetic field (H); so 4n portions are required to measure n turns. The invention has application in measuring the rotation of a shaft, particularly a vehicle steering wheel shaft. |
