scholarly journals Magnetic Liquid Switching Using Rodlike Ferronematic 6CHBT Liquid Crystal Mixture Depending on the Diffraction Patterns

2021 ◽  
pp. 465-474
Author(s):  
Rawa K. Ibrahim ◽  
Aseel I. Mahmood ◽  
Veronika Gdovinova ◽  
Peter Kopcansky

Diffraction patterns formed by a ferronematic sample, which contains 4-(trans-4-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT) liquid crystal doped with Fe3O4 rodlike magnetic nanoparticles, was studied. The studied mixture can be applicated as a liquid magnetic switch. The diffraction patterns were observed from the micro-lines scribed on the polymer layer, which was contained by the liquid crystal mixture cell, with dimensions of 4 nm for depth and 0.32 µm for width and 5000 line per 1 mm2 in the case of absence and presence of the DC magnetic field. From the experimental results, it was observed that the application of the magnetic field caused more than 17% expansion in the diffraction patterns area at the focused point, while the number of patterns was increased by 25%. This change in the diffraction area due to the application of a magnetic field gives the motive to sense the low DC magnetic field which could be useful in the application of liquid switching.

Soft Matter ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1279-1294 ◽  
Author(s):  
Alena Antipova ◽  
Colin Denniston

We explain the motion of a micron-sized ferromagnetic disc immersed in a nematic liquid crystal under the action of a weak magnetic field using numerical simulations. We show that the disc's behaviour can be controlled by the angular speed of the magnetic field and its magnitude.


2020 ◽  
Vol 16 (11) ◽  
pp. 1623-1632
Author(s):  
Abbas Moghanizadeh ◽  
Fakhreddin Ashrafizadeh ◽  
Jaleh Varshousaz ◽  
Mahshid Kharaziha

This study aims to evaluate the efficiency of a novel in vitro technique in clot capturing and dissolving them by applying magnetic force on magnetic nanoparticles (MNP) carrying thrombolytic agents. It is a quick and simple method to protect patients from a life-threatening pulmonary embolism in an emergency to provide time for the medical team. To analyze the in vitro efficiency of nano-magnetic capturing and dissolving of clots (NCDC), different levels of process parameter including strength magnetic field (0.1, 0.2 and 0.3 T) and fluid flow rate (2.5, 5 and 7 l/min) are exposed to different blood clots sizes from 5 × 10 to 20 × 10 mm2 (length × diameter), in an in vitro flow model. The results show that by increasing the parameters to their maximum values, it is possible to immobilize 100% of the clots and dissolve around 61.4% of clots weight. In addition, the clot-dissolving is directly proportional to the magnetic field strength. NCDC is an efficient technique in immobilizing and dissolving the clots and its efficiency depends on process parameters especially the magnetic field.


2018 ◽  
Author(s):  
Mahendran Subramanian ◽  
Arkadiusz Miaskowski ◽  
Stuart Iain Jenkins ◽  
Jenson Lim ◽  
Jon Dobson

AbstractThe manipulation of magnetic nanoparticles (MNPs) using an external magnetic field, has been demonstrated to be useful in various biomedical applications. Some techniques have evolved utilizing this non-invasive external stimulus but the scientific community widely adopts few, and there is an excellent potential for more novel methods. The primary focus of this study is on understanding the manipulation of MNPs by a time-varying static magnetic field and how this can be used, at different frequencies and displacement, to manipulate cellular function. Here we explore, using numerical modeling, the physical mechanism which underlies this kind of manipulation, and we discuss potential improvements which would enhance such manipulation with its use in biomedical applications, i.e., increasing the MNP response by improving the field parameters. From our observations and other related studies, we infer that such manipulation depends mostly on the magnetic field gradient, the magnetic susceptibility and size of the MNPs, the magnet array oscillating frequency, the viscosity of the medium surrounding MNPs, and the distance between the magnetic field source and the MNPs. Additionally, we demonstrate cytotoxicity in neuroblastoma (SH-SY5Y) and hepatocellular carcinoma (HepG2) cells in vitro. This was induced by incubation with MNPs, followed by exposure to a magnetic field gradient, physically oscillating at various frequencies and displacement amplitudes. Even though this technique reliably produces MNP endocytosis and/or cytotoxicity, a better biophysical understanding is required to develop the mechanism used for this precision manipulation of MNPs, in vitro.


2011 ◽  
Vol 287-290 ◽  
pp. 603-607
Author(s):  
Chun Lin Xia ◽  
Yang Fang Wu ◽  
Qian Qian Lu

Using domestic MFSP membrane as a medium of energy conversion, a kind of MFSP actuator was designed. The dedicated test equipment was constructed for experimental research, and the experimental results were given. The strip and circular MSFP membrane were analyzed qualitatively to obtain the deformation characteristics of membrane by finite element analysis software.


2018 ◽  
Vol 185 ◽  
pp. 09006
Author(s):  
Alexander Tyatyushkin

Small steady-state deformational oscillations of a drop of magnetic liquid in a nonstationary uniform magnetic field are theoretically investigated. The drop is suspended in another magnetic liquid immiscible with the former. The Reynolds number is so small that the inertia can be neglected. The variation of the magnetic field is so slow that the quasi-stationary approximation for the magnetic field and the quasi-steady approximation for the flow may be used.


2011 ◽  
Vol 10 (03) ◽  
pp. 515-520 ◽  
Author(s):  
SI-HUA XIA ◽  
JUN WANG ◽  
ZHANG-XIAN LU ◽  
FEIYAN ZHANG

We report magneto-optical properties in a kerosene colloidal suspension of oleic acid coated Fe3O4 nanoparticles (~14 nm). The magnetic colloids (fluids) show birefringence under a magnetic field. Systematical studies of the on–off switch times upon application of the on–off magnetic field with varied experimental parameters indicate that the switch response time depends strongly on the strength of the magnetic field and the concentration of the magnetic nanoparticles in the fluid. The data can be explained in terms of the formation of magnetic nanoparticle chains under a magnetic field. The important magneto-optical properties of the magnetic fluids allow us to design a tunable optical switch.


1974 ◽  
Vol 29 (9) ◽  
pp. 1356-1366 ◽  
Author(s):  
G. Heppke ◽  
F. Schneider

Inversion walls are generated by rotating the direction of a magnetic field by 180° with respect to the director in the homeotropically aligned nematic layer. A numerical procedure based on the Leslie-Ericksen theory allows for the calculation of the dynamic behaviour of the inversion walls. Experimental results obtained with MBBA by electric conductivity measurements show satisfying agreement with theory.


2017 ◽  
Vol 898 ◽  
pp. 1783-1786
Author(s):  
Lei Zhang ◽  
Yi Su ◽  
Yu Lin Wu ◽  
Yao Liu ◽  
Yong Wang ◽  
...  

The viscosity of potassium dihydrogen phosphate, KH2PO4 (KDP), aqueous solution within magnetic field was studied. Experimental results showed that, the viscosity of saturated KDP solution exhibited multiple extreme values when the magnetic field intensity increased from 0 Gs to 2250 Gs. Influences of the magnetic field intensity on the viscosity of KDP solution were very complicated. It’s concerned with the temperature and the concentration of solution. As the KDP was produced from aqueous solution within magnetic field, the temperature and the concentration of solution also needed to be carefully controlled. Magnetic field with intensity values of 300 Gs, 600 Gs and 1800 Gs, all have the strong effects on the structures of KDP aqueous solution.


2004 ◽  
Vol 820 ◽  
Author(s):  
Ramazan Asmatulu ◽  
Richard.O. Claus ◽  
Judy S. Riffle ◽  
Michael Zalich

AbstractBiodegradable magnetic nanoparticles were synthesized using Poly(L-Lactic Acid) and magnetite nanoparticles (∼14 nm) at different dosages, and then these nanaoparticles (nanocomposites) and pure magnetic particles were targeted in external magnetic fields by changing the test parameters. The magnetic field test results showed that magnetic saturation, fluid speed, magnetic field distance and particle size were extremely effective for a magnetic guidance system that is needed for an effective drug delivery approach. Thus, it is assumed that such nanoparticles can carry drugs (chemotherapy) to be able to cure cancer tumors as well as many other diseases.


2011 ◽  
Vol 101-102 ◽  
pp. 202-206 ◽  
Author(s):  
Guo Liang Hu ◽  
Miao Guo ◽  
Wei Hua Li

In this study, the MRE was manufactured, and the sandwich beam was also fabricated by treating with MRE between two thin aluminum layers. The experiment test rig was set up to investigate the vibration response of the MRE sandwich beam under non-homogeneous magnetic field. The experimental results show that the MRE sandwich beam had the capabilities of left shifting first natural frequency when the magnetic field was increased in the activated regions. It is also obvious that the first natural frequency of the MRE sandwich beam decreased as the magnetic field that applied on the beam was moved from the clamped end of the beam to the free end of the beam.


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