Hanuman's science fair presentation, 2011

1. Ferrofluid:
An in-depth study

2. What is Ferrofluid?
Ferrofluid, Latin ferrum—iron
and fluid, is a colloidal
suspension, composed of
ferromagnetic nano-particles
in a liquid, such as water, or
some type of oily fluid.

3. Nanoparticles
• Nanoparticles are objects that are measured in
nanometers. Nanometers are 1/100 of a micrometer.
Anything measured in micrometers is microscopic so you
can imagine the size of a nanoparticle.
• The magnetic nanoparticles in ferrofluid are less
than 10 nanometers in diameter. Compare this to the
size of a water molecule at 0.278 nanometers.

4. Normal-field instability
When a paramagnetic fluid is brought near a strong vertical magnetic
field, the surface forms a regular pattern of peaks and valleys. This
effect is known as the normal-field instability. The instability is
driven by the magnetic field; it can be explained by considering
which shape of the fluid minimizes the total energy of the system.
The reason ferrofluid does this is because it wants to reach out
into space as far as possible. Therefore moving fluid out in some
places, and up onto others increases its height.

5. Paramagnetism
Paramagnetism is a form of
magnetism that occurs only in the
presence of an externally applied
magnetic field. The paramagnetic
particles in ferrofluid only become
magnetic when a naturally magnetic
object comes into contact with them.

6. Ferrofluid is a Colloid
• A colloid is a substance, like Gas Liquid Solid
milk, which is composed of
billions of particles, Gas none fog smoke
microscopically dispersed (gas naturally
through a continuous medium. miscible)
Liquid whipped milk ferro-
• Ferrofluid is a Solid in liquid cream
fluid
type colloid. This means that it
is the same as blood when it Solid aero- Jello cranberry
-glass
comes to colloid type gel

7. Uses of Ferrofluid
• Medicine: Cancer detection and magnetic
hyperthermia to cure cancer.
• Optics: Shape shifting mirror for
telescopes.
• Engineering: Ferrofluid reduces friction
and is used to form liquid seals around
hard drives. NASA is also experimenting
with ferrofluid in spacecraft, to influence
rotation.
• Art: Sachiko Kodama is known for
her ferrofluid art and Concept zero,
an American art studio creates
conversation pieces that use
ferrofluid.

8. Ferrofluid vs. MR fluid
Ferrofluid and MR fluid are different in many ways. For instance,
ferrofluid does not settle whereas MR fluid’s larger particles will go
to the bottom over time. This means that unlike ferrofluid it must be
replaced over time.

9. E-Ink
• E-ink is electronic paper developed by E-
ink Corporation and based of research at
the MIT lab. It is currently available in
grayscale and color.
• It is based on the idea that if there are
positively charged white and negatively
charged black particles, depending on the
influence it will change the color of the
display.
• I used the principle of E -ink to conduct an
experiment involving Ferrofluid

10. Thank you for watching
I will now show a small video and after that you
may come to my table where there is an
interactive Ferrofluid display.