Ferrofluids are stable liquid solutions containing magnetic nanoparticles that become strongly magnetized in the presence of a magnetic field. They were invented in 1963 by NASA scientist Steve Papell to create rocket fuel that could be pumped in zero gravity. Ferrofluids have applications in precision engineering, drug delivery, hyperthermia cancer treatment, and body armor. They can be used to transport drugs to target areas or generate heat for cancer treatment when exposed to magnetic fields. New body armor using ferrofluids in hollow fibers could act as an artificial splint. Ferrofluids also have potential applications in areas like lubrication and speakers due to their magnetic and thermal properties.

1. Ferrofluids and
their Applications
Shivansh Gour
Roll no. 18ME79
For any queries: sg.android.dev.ld@gmail.com
Guide :- Mr.Vineet Singh
Co-Guide :- Ms.Shashi Lata
DEPARTMENT OF MECHANICAL ENGINEERING,
F.E.T M.J.P.R.U BAREILLY

2. Content Table
● WHAT IS FERROFLUID?
● STRUCTURE OF FERROFLUIDS
● PROPERTIES OF FERROFLUID
● APPLICATIONS OF FERROFLUIDS
● CONCLUSION
● REFERENCES

3. What is the Ferrofluid?
● A Ferrofluid is a liquid which becomes highly magnetized in the presence of a magnetic
field.
● Ferrofluids are the stable colloidal solution of nano magnetic particles infused with
carrying fluid, usually water or organic solution.

4. History of the compound
● Ferrofluid was invented by NASA’s Scientist
Steve Papell in 1963. The objective of
developing ferrofluid was to create rocket fuel
that could flow toward the fuel pump in
absence of gravity by implying a magnetic
field.
● First confirmed application of ferrofluid was
during “ The Apollo Moon Landing Mission”.

5. Structure of Ferrofluids
● The composition of a typical ferrofluid is about 5% magnetic solids, 10% surfactant and
85% carrier, by volume. Particles in ferrofluids are dispersed in a liquid, often using a
surfactant, and thus ferrofluids are colloidal suspensions – materials with properties of
more than one state of matter. Generally size of single domain magnetic particle lies
between 5-10nm
● There are two type of ferrofluids: 1. Surfactant FerroFluid 2. Ionic Ferrofluid
The soapy surfactants used to coat the
nanoparticles include, but are not limited to:
1. Oleic acid
2. Tetramethylammonium hydroxide
3. Citric acid
4. Soy lecithin

6. Properties of ferrofluid
● Magnetization:When ferrofluids are subjected to an external magnetic field, the
tendency of fluid particles to align with the field is counteracted by thermal
agitation and when the magnetic field is removed fluid particles come back to their
randomness.

7. ● Ferrofluid Viscosity:In ferrofluids, a magnetic field causes changes in its
rheological properties. There are two factors that cause change in viscosity:
first is rotational viscosity and second particle chain and this phenomenon
known as magneto viscous effect.

8. ● Rosensweig instability:Ferrofluids subjected to a sufficiently large magnetic
field exhibit surface instabilities or sudden change from flat horizontal
surface to hexagonal pattern of spikes known as Rosensweig instability.
These spiky structures are formed to minimize magnetic and surface energy
in the system. The magnetic energy is minimum at peaks and valleys and the
surface energy is minimum for completely flat surfaces.

9. ● Ferrohydrodynamics : In ferrohydrodynamics we study the flow of ferrofluids
in which we study the navier-stokes equation. The Navier-stokes equation
flow of incompressible ferrofluid in influence of magnetic field can be defined
by the navier-stokes equation; this relation is given for ferrofluids at which
external magnetic(M) field is parallel to inner magnetic field(H).

10. ● Major benefit of ferrofluid is that the liquid can be forced to flow via the positioning and
strength of the magnetic field and so that ferrofluid can be positioned very exactly.
● Ferrofluids also have the capability to reduce friction, making them useful in a variety of
electronic and transportation application
● Ferrofluid can have high thermal conductivity and their heat transfer properties are
exploited in devices such as loud speakers where they used to cool the voice coil.
● Ferrofluid lose their magnetism as they are heated, fully losing their magnetic properties
when heated to a high enough temperature, known as the Curie Temperature.
Some other useful properties of ferrofluids

11. Application of Ferrofluids in Drug Delivery
● Ferrofluid are also the focus of current
scientific research and having the
potential to be used in various medical
applications. In magnetic drug targeting
for example, where drug could be enclosed
by ferrofluid and, once injected into the
specific body area requiring treatment, a
magnetic field could be applied to keep
drug in this target area. The localization
would limit exposure to the rest of the
body and enable the dosage level to be
decreased, reducing the adverse side
effects experienced by the patient.

12. Magnetic Hyperthermia
● Magnetic hyperthermia is an
experimental treatment for cancer,
based on the fact that magnetic
nanoparticles can transform
electromagnetic energy from an
external high-frequency field to heat.
This is due to the magnetic hysteresis
of the material when it is subjected to
an alternating magnetic field (AMF).
The area enclosed by the hysteresis
loop represents losses, which are
commonly dissipated as thermal
energy

13. Applications of ferrofluid in Body Armour
● Ferrofluids could be used to keep us safe too:
new body armour is being developed by M.I.T
which utilises ferrofluid in hollow fibers, this
body armour could act as a artificial splint in the
heat of battle.
● The mechanism of this armour is when an
external load is applied on body, pressure sensor
sense the load and activate magnetic field in fiber
due to magnetic field chain formation formed
and that absorb the load/impact.

14. Application of Ferrofluids in Precision
Engineering
● Ferrofluid based applications have huge potential in field of Precision Engineering due to their low
vapour pressure and their magnetization property make them suitable to work in zero gravity.
● Ferrofluid based planer bearings have no stick-slip phenomenon, therefore they gives us high
precision in their application.
● Problem with these bearing is trail formation that reduces flight height of bearing as well as load
bearing capacity.
● It has been observed that a bearing with a diameter of 24.5 mm is capable of carrying a load of
approximately 8 N with a stiffness of approximately ∼2×10^4N/m.
● This figure is example of Pocket
bearing, as we can see there is no
direct contact due to magnetic
pressure hence there is no stick-slip
condition.

15. Conclusion
● To conclude we can say that application of ferrofluids have huge potential and there are
very few researches conducted in this field.
● Contribution to our society of Ferrofluid is increasing day by day from space technology
to medical science and even in our daily life like; lubricant in MSME, collant in loud
speakers etc
● There are some problems also associated with ferrofluid like no proper mathematical
model available to design ferrofluid bearing, trail formation etc.
● In order to make India self reliable in defence sector ferrofluid could play significant role
in it to make stronger and cheaper armours.

16. References
● Wikipedia:Ferrofluid, https://en.wikipedia.org/wiki/Ferrofluid.
● Stefan G.E. Lampaert,Planar Ferrofluid Bearings Modelling and Design Principles. Delft
University of Technology.
● Holger Knieling,Reinhard Richter,Ingo Rehberg,Gunar Matthies,and Adrian Lange Growth
of surface undulations at the Rosensweig instability, PACS numbers: 47.20.Ma, 47.54.-r,
75.50.Mm
● Lakshita Phor and Vinod Kumar,Self-cooling by ferrofluid in magnetic field,SN Applied
Sciences (2019) 1:1696 | https://doi.org/10.1007/s42452-019-1738-z