ExpertiseElectromagnetic Sensors

Electromagnetic Sensors

Our Electromagnetic Sensor Unit works with sensor systems involving various magnetic-detection techniques.

Together with customers from both large and small companies as well as in academia projects, we develop sensor systems and assist in magnetic analysis and characterization. Magnetic and electric sensor systems can be applied when for instance object position and motion must be detected wirelessly, moisture and viscosity detection and wireless force and torque measurements. Our outstanding laboratory facilities and deep magnetic knowledge enable us to carry out both static and dynamic magnetic characterization of magnetic materials.

General magnetic sensing

Most magnetic sensor systems consist of a magnetic-field sensor that measures the magnetic field in one or more directions and a magnetic element that creates the magnetic field. Different kinds of stimuli for instance changes the distance or the orientation of the magnetic element with respect to the magnetic field sensor or the magnetic properties of the material in the magnetic element, which can be detected by the sensor. Thus, a magnetic sensor system can not just detect the magnetic field but also detect all kinds of parameters such as distance, orientation, forces, motion, leakage, presence of vehicles or even different kinds of biomolecules in a liquid. We are also building and sell sensitive magnetic characterization system in order to detect the dynamic magnetic properties of magnetic materials for instance magnetic particles in liquids, magnetic powders and magnetic films.

Magnetic analysis and magnetic nanoparticles

In the course of our activities, we work with magnetic nanoparticles and magnetic materials to assist our customers in the characterization of magnetic materials. In the magnetic analysis we work with static magnetic analysis (VSM) and dynamic magnetic analysis (AC susceptometry). In the magnetic analysis we also combine the experimental results with magnetic modeling in order to understand the magnetic systems in detail. To complement our expertise, we also provide magnetic courses to industry or acedemia. These courses cover areas such as general magnetism, magnetic materials and magnetic nanoparticles as well as the magnetic nanoparticle systems used in bio-application systems.

Magnetoelastic resonance

A magnetoelastic material changes its dimensions when it is exposed to a magnetic field. Exposing the film to a short magnetic pulse excites the film, and it starts to oscillate. The frequency, amplitude and damping of the vibration give information about the status of the sensor. Properties of a media, such as its viscosity, density, pressure and flow speed, can be determined by analyzing the response of a magnetoelastic film placed in the media. It is also possible to follow a dynamic event, such as the curing process of glue and paint or moisture uptake in paint. The magnetoelastic film can be sensitive to many physical properties by coating it with various materials.  For example, a wireless humidity sensor can be constructed by coating the film with a humidity-absorbing material. When the humidity sensor is placed in a humid environment, the coating will absorb water and become heavier and the resonance frequency decreases.

Magnetic simulations

Simulation is a powerful tool when designing sensors and sensor systems. By combining simulations based on the finite element method (FEM), with our great skills in material properties, measurement techniques, electronic design and signal processing, we a have great platform for solving difficult problems within the field of magnetic and electric systems. We are using COMSOL Multiphysics® in combination with the AC/DC module to model and study a wide range of magnetic and electric phenomenon. The simulations have played an important role in many recent projects involving for example coil design, magnetic material characterization, magnetic force calculations, magnetic pattern applications, demagnetization effects of arbitrary objects, magnetic nanoparticle interactions and capacitive sensor design.

People

Fredrik Ahrentorp
Research Engineer
+46 (0)70 915 18 30
fredrik.ahrentorp [at] ri.se

Jakob Blomgren
Senior Scientist
+46 (0)70 915 18 48
jakob.blomgren [at] ri.se

Christer Johansson
Senior Expert, Professor
+46 72 723 33 21
christer.johansson [at] ri.se

Christian Jonasson
Group Manager / Project Manager / Research Scientist
+46 70 915 18 41
christian.jonasson [at] ri.se

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