ResearchActivities

Magnetically active smart materials

Abstract:
This research focuses on understanding the rheological and transient behaviour of magnetorheological (MR) fluids and elastomers to enhance the comprehension of the magnetorheological effect.

Main objectives:

  • To comprehend and describe the rheological behaviour of magnetorheological fluids in "pinch" load mode under non-uniform magnetic fields.

  • To analyse and quantify the speed of particle chain formation in magnetorheological fluids during step excitation in the magnetic field.

  • To investigate the transient behaviour of magnetically active elastomers.

Research content:
The research is centred on the study of magnetorheological (MR) fluids and magnetorheological elastomers, both of which are crucial for advancing the understanding of magnetically responsive smart materials.

MR fluids are suspensions of micro-sized ferromagnetic particles in a carrier fluid with additives. When an external magnetic field is applied, the particles form chains, leading to a significant increase in the fluid's apparent viscosity. Key challenges in this field include understanding the chaining mechanism of particles during a step change in the magnetic field and describing the rheological behaviour and microstructure in "pinch" loading mode. The research team has developed a novel method and device to experimentally determine the speed of chaining of particles in MR fluids, successfully generalizing their findings through dimensionless parameters such as the Bingham and Mason numbers. The team has also been pioneering in using fluorescence microscopy to observe and describe, for the first time, the microstructural behaviour of MR fluids under non-uniform magnetic fields in "pinch" loading mode. Observations confirmed the existence of a Venturi-like contraction, whose dimensions can be controlled by adjusting the magnetic field level. These findings are critical for a more profound understanding of the magnetorheological effect, which has wide-ranging implications in smart material applications.

MR elastomers are composite materials that incorporate ferromagnetic particles within an elastomeric matrix. When exposed to an external magnetic field, these materials exhibit changes in stiffness, damping, and dimensions due to the magnetostriction effect. The main challenge in this area is to understand the transient behaviour of MR elastomers, which is essential for developing more effective and faster microscale soft robots. The team has conducted extensive experimental studies to detail how the transient behaviour of these materials varies under different magneto-mechanical loading scenarios. This research not only advances the fundamental understanding of magnetorheological effects but also paves the way for innovative applications in smart robotics and adaptive engineering systems.

Publications:
KUBÍK, M.; BORIN,D; ODENBACH,S. Transient dynamics of the field induced force in the isotropic magnetorheological elastomer. Smart Materials and Structures, 2023, vol. 32, no. 6, p. 1-11. ISSN: 1361-665X. https://doi.org/10.1088/1361-665X/acd0e5

KUBÍK, M.; VÁLEK, J.; ŽÁČEK, J.; JENIŠ, F.; BORIN, D.; STRECKER, Z.; MAZŮREK, I. Transient response of magnetorheological fluid on rapid change of magnetic field in shear mode. Scientific Reports, 2022, vol. 12, no. 1, p. 1-10. ISSN: 2045-2322. https://doi.org/10.1038/s41598-022-14718-5

KUBÍK, M.; ŽÁČEK, J.; GOLDASZ, J.; NEČAS, D.; SEDLAČÍK, M.; BLAHUTA, J.; BAŃKOSZ, W.; SAPINSKI, B. Grasping the behavior of magnetorheological fluids in gradient pinch mode via microscopic imaging. PHYSICS OF FLUIDS, 2024, vol. 36, no. 4, p. 042004-1 (042004-10 p.) ISSN: 1070-6631. https://doi.org/10.1063/5.0203804

Partners and Collaboration:
Technische Universität Dresden, Mommsenstraße 11, 01069 Dresden Germany.

Cracow University of Technology, Warszawska 24, 31-155 Kraków, Poland.

AGH University, al. Adama Mickiewicza 30, 30-059 Kraków, Poland.

University of Granada, Avenida del Hospicio, S/N, Granada, Spain.

Universiti Teknologi Malaysia, Jalan Iman, 81310 Skudai, Johor, Malaysia.

Projects:
Study of the Magnetorheological Fluid Response Time, Czech Science Foundation, Junior grant, 20-23261Y, 2020-2022.

Rheology of magnetorheological fluids subjected to non-uniform magnetic fields – pinch mode, Czech Science Foundation, LA grant, 21-45236L, 2021-2024.

Contact person:
doc. Ing. Michal Kubík, Ph.D.