Magnetic sensors

Magnetic sensors have a myriad of uses, from infrastructure inspection to traffic management. Our industry-led research is exploring further applications.

 Manufacturing state-of-the-art magnetic thin film materials.
Manufacturing state-of-the-art magnetic thin film materials.

We are researching magnetoresistive materials, which change their resistance in response to a magnetic field, and how these materials can be utilised in magnetic sensors.

Magnetoresistive materials can change their resistance in a magnetic field directly as well as when they are incorporated into a multi-layered structure. These multi-layered materials form the basis of spintronics, a field of research where the conducting properties of a material are manipulated via the spin of the electrons, as well as their charge.

Our research has sought to increase the control of electron spin in Heusler alloys and double perovskite oxides. We are also investigating semiconductors that have a strong linear magnetoresistance. These properties will enable magnetic sensors with higher performance to be developed for specific applications.

Applications

We work with industry partners to make new devices and systems and can create magnetic sensor prototypes to meet an industry need. We also build systems using commercially available sensors, which requires an understanding of how the sensor will perform and interact with the system.

Non-destructive testing

The integrity of critical metal infrastructure can be tested using eddy current techniques. These methods detect an induced magnetic field with giant magnetoresistance (GMR) sensors rather than by measuring the impedance of a coil.

The advantage of GMR is the option of using lower frequencies. This allows excitation currents to penetrate deeper into the metal structure.

Applications of this technology include:

  • testing the structural integrity of metal components such as pipes in the oil and gas industry
  • testing the production quality of tubes, bars and wires
  • inspecting welds
  • inspecting metal surfaces for cracks and corrosion.

Magnetic detection

Any object that has magnetic properties can be detected using a sensor. This technology is applied in many settings, including the identification of metal contaminants in food, detecting cars on a road or manipulating magnetic nanoparticles within a biological system.

We are working with a range of industries to develop new applications for magnetic sensors.

Facilities and instruments

We have the following facilities and instruments in house to support our magnetic sensor research:

  • high performance Teslameter to accurately measure magnetic fields
  • Kurt J Lesker multi-target sputter system for making thin film materials and sensor contacts
  • PPMS and SQUID systems to measure magnetic fields up to 90,000 Oe and temperatures from –271°C to 127 °C
  • sensor structure computer-assisted design
  • clean room facilities for custom sensor processing.

System development

We develop prototype devices and systems such as:

  • electronics for low frequency magnetic field excitation and sensor interrogation
  • electromagnetic finite element modelling (FEM) and ANSYS and OPERA for optimum sensor and system design
  • signal processing algorithms.

Publications

View a list of our recent magnetic sensors publications.