DynoMag – a magnetic measuring system for many applications

Highly interesting work and research are currently underway in defining and standardizing various nanostructures. To enable effective research, reliable and standardized measuring instruments and methods are required. At the RISE Magnetic Sensor Systems Lab, we have successfully developed and standardized measurement instruments and methodology for dynamic magnetic measurement and analysis, which are part of standardized measurement systems for MNPs.

Christer Johansson, senior expert at the Sensor Systems unit at RISE, explains that in dynamic magnetic measurements, an alternating (AC) magnetic field with a specific frequency and amplitude is used on the sample. The resulting dynamic magnetic response, also called AC-susceptometry (ACS), is measured contactless through coils and sensitive magnetic measurement technology.

“The DynoMag system, developed and manufactured at the RISE Magnetic Sensor Systems Lab in Gothenburg, has been central in over 160 scientific articles, particularly in the magnetic analysis of MNP systems. The goal has always been to create a sensitive and user-friendly measurement system with integrated electronics and software, along with associated magnetic models for accurate analysis of measurement data”, says Christer.

The development of DynoMag and other similar ACS systems has been conducted in both internal projects and several EU projects, as well as nationally funded projects. Through the EU projects NanoMag and MagNaStand, the DynoMag system and the measurement methodology have been further developed, resulting in an approved ISO standard for ACS measurement methodology for MNPs. 

“By sweeping the frequency and measuring the sample response, the DynoMag system, with its magnetic models, can identify magnetic relaxations and determine the particle size distribution for MNP systems in colloidal solution”, Christer continues.

Another application is monitoring the stability of MNP systems over time under external influences, or as a quality assurance method in the manufacturing of MNP systems to maintain optimal properties or develop new applications. The ACS response in the frequency domain varies depending on the MNP configuration and the presence of particle aggregates.

Through ACS measurement technology and optimal MNP systems, rheological properties can be determined for different substances, from simple Newtonian fluids, like water and glycerol solutions, to complex non-Newtonian substances like gelatin and Xanthan solutions used in the food industry. In a successful project funded by Formas, RISE, together with Chalmers University of Technology, utilized ACS measurement methodology and optimal MNP systems to measure viscoelastic properties in food research. 

The DynoMag ACS system also enables sensitive detection of biological markers by measuring and analyzing the response from functionalized MNP systems. A successful project in collaboration with Chalmers University of Technology, Karolinska Institute, Uppsala University, and Stockholm University, funded by SSF, resulted in an integrated measurement system for influenza. 

“In summary, the DynoMag system is a key component for the characterization of magnetic nanostructures, rheological studies, and biomedical research, with its applications spanning across various disciplines and fields”, Christer concludes.