Ferrofluid
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Ferrofluid is a colloidal liquid that contains magnetic nanoparticles. When exposed to a magnetic field, the nanoparticles align and cause the ferrofluid to take on regular shapes like peaks and valleys. This "normal-field instability" occurs because the ferrofluid seeks to maximize its exposure to the magnetic field. Ferrofluid remains in liquid form and finds many applications, from sealing hard drives to cancer detection and treatment using magnetic hyperthermia. It differs from similar magnetic fluids in its ability to remain suspended rather than settling over time.
Ferrofluid
- 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.