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Published on: August 28, 2017
Magnetically Induced Ferrofluid Droplet Manipulation on Slippery Surfaces.
Yehao Qin1, Zeeshan Anjum1, Qingwen Dai1
1College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China.
Langmuir : the ACS Journal of Surfaces and Colloids
|July 15, 2026
Summary
Magnetic fields deform ferrofluid (FF) droplets on slippery liquid-infused porous surfaces (SLIPS). Particle concentration strongly influences deformation, enabling predictable control and presplitting for FF manipulation.
Area of Science:
- Fluid dynamics
- Materials science
- Magnetohydrodynamics
Background:
- Ferrofluid (FF) droplet manipulation is hindered by contact-line pinning and contamination on conventional surfaces.
- Slippery liquid-infused porous surfaces (SLIPS) offer a promising alternative for droplet manipulation.
- Understanding magnetic-field-induced deformation is crucial for advanced FF applications.
Purpose of the Study:
- To investigate magnetic-field-induced deformation and presplitting of FF droplets on SLIPS.
- To analyze the influence of magnet geometry, droplet volume, particle mass fraction, and droplet-magnet distance.
- To develop predictive models for FF droplet behavior on SLIPS.
Main Methods:
- Utilized side-view imaging and image-based profile analysis.
- Systematically varied FF droplet parameters (volume, particle mass fraction) and magnetic field parameters (magnet geometry, distance).
- Employed symbolic regression to derive empirical correlations for droplet deformation.
Main Results:
- Observed decreased apparent contact angle and base width, with increased droplet height as magnet approached.
- Demonstrated that FF particle mass fraction had the strongest influence on deformation mode.
- Developed predictive models with R² values of 0.94 (height) and 0.89 (width) for droplet deformation.
Conclusions:
- FF droplets can be controllably deformed and presplit on SLIPS using magnetic fields.
- The study provides empirical correlations for predicting FF droplet morphology on SLIPS.
- This research advances non-contact manipulation techniques for ferrofluids.
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