Researchers from IBM Research labs in Zurich developed a Spintronics based small-sized, low cost non-optical, non-contact position sensor. This sensor detect changes in a high-gradient magnetic field of a microscale magnetic dipole. The sensor can achieve sensitivities of up to 40 Ohm/µm, which leads to a noise floor of 0.5 pm/sqrt(Hz) over more than a megahertz bandwidth.

Magnetoresistance-based position sensors have been known for a long time, but their use in nanotechnology was limited due to a relatively low sensitivity and a large amount of hysteresis. These issues were solved by IBM by operating the spintronic sensor close to the pole of a micromagnetic dipole. This is where the magnetic field has an extremely high gradient, which increases as the dimensions of the micromagnet are scaled down.