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Updated: Nov 24, 2025
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An Additive Manufacturing Technique for the Facile and Rapid Fabrication of Hydrogel-based Micromachines with Magnetically Responsive Components
Published on: July 18, 2018
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Reinforcing Magnetorheological Fluids with Highly Anisotropic 2D Materials
Abigail Rendos1, Ran Li2, Stephanie Woodman3
1Division of Materials Science and Engineering, Boston University, 15 St. Mary's Street, Boston, 02215, USA.
Summary
Adding 2D nickel hydroxide sheets to magnetorheological fluids (MRF) can increase pressure resistance but may weaken performance by disrupting particle alignment. Anisotropy offers a new way to tune smart fluid properties.
Area of Science:
- Materials Science
- Fluid Dynamics
- Rheology
Background:
- Magnetorheological fluids (MRF) are smart fluids whose properties change under a magnetic field.
- Understanding the impact of non-magnetic additives, especially their morphology, on MRF performance is crucial.
- Highly anisotropic additives offer potential for novel MRF tuning.
Purpose of the Study:
- To investigate the effect of 2D α-Ni(OH)2 sheets as anisotropic additives in MRF.
- To explore how these additives influence MRF behavior under different flow conditions and magnetic field strengths.
- To reconcile seemingly contradictory effects of the additives on MRF performance.
Main Methods:
- Synthesized and characterized 2D α-Ni(OH)2 sheets with high aspect ratios.
- Conducted experiments on pressure-driven flow of MRF with and without the 2D sheets.
- Performed shear-mode rheology tests to evaluate MRF behavior under varying magnetic fields.
- Modified the Buckingham-Reiner model to account for the influence of 2D additives.
Main Results:
- Addition of 2D sheets increased saturation pressure by up to 46%.
- Shear rheology showed weakened MRF performance at low magnetic fields due to inhibited iron particle chaining.
- No significant effect on performance was observed at high magnetic field strengths.
- The 2D materials introduced a non-Newtonian behavior dependent on shear strain rate curvature.
Conclusions:
- 2D anisotropic additives can significantly alter MRF properties, offering a tunable mechanism.
- The observed effects depend on the interplay between additive morphology, magnetic field strength, and flow conditions.
- This study highlights the potential of exploiting anisotropy in additives for advanced smart fluid design.
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