Ferrofluids: The Magnetic Liquid Dancer

The 1900s brought about countless exciting inventions from all across the globe. Sometimes a little mysterious, many of these inventions were intriguing and versatile. One such invention was the ferrofluid, a substance that serves a variety of purposes in fields ranging from rocket science to school science fairs. Ferrofluids are commonly recognized as spiky liquids that “dance” under the influence of magnetic fields. Technically defined, ferrofluids are stable colloidal suspensions of superparamagnetic iron oxide nanoparticles. The magnetic property of ferrofluids derives from these tiny iron oxide particles. Because of these nanoparticles, ferrofluids do not stay magnetized after being removed from the presence of a magnetic field. Patented in 1965 by NASA chemist Steven Papell at the Lewis Research Center, ferrofluids were initially developed by scientists intending to facilitate the transfer of rocket fuel into a spacecraft’s engine. In space, the lack of gravity allows fuel to float within the holding tank and makes it difficult for the fuel to be efficiently pumped into the engine. Papell envisioned transforming the non-magnetic fuel into one that could be controlled and guided by the maneuvering of magnetic fields. Although Steven Papell’s idea was never practiced (as NASA preferred the use of solid rocket fuel to the concept of liquid magnetic fuel), it did incite the fervor to research this new magnetic substance. In fact, there was so much excitement surrounding ferrofluids that the mechanics of magnetic fluids was recognized as a new branch of science known as Ferrohydrodynamics. Even after the rapid development of solid rocket propulsion technology eliminated the need for magnetic fuel, ferrofluids did not leave the realm of rocket science. Only a few years after their invention, ferrofluids were reconsidered for use in rockets, but this time to manage the spacecraft’s temperature: the temperature of the side of the rocket facing the sun is significantly higher than that of the side in shadow, which can introduce problems to the spacecraft. More recently, it was also found that ferrofluids could improve speakers. In loudspeakers, electric energy is sent through a coil near the center of a circular permanent magnet. The current running through the coil induces a magnetic field, causing the coil to vibrate and produce an amplified sound. By coating the coil in a ferrofluid, engineers are able to dampen unwanted resonances and dispel excess heat from the coil. As a result, the speaker is able to have better sound quality. Nowadays, ferrofluids are being developed and tested for potential use in the biomedical field. Medical researchers are hopeful that with magnetic fields, medicine can be transferred quickly and easily through the human body. Ferrofluids are also being used in magnetic resonance imaging (MRI) techniques as contrast agents. In this fast-paced new era when inventions and innovations are constantly springing up from every corner, ferrofluids are no exception. Engineers and scientists in every field are coming up with more enhanced and creative ways to employ ferrofluids within their work. One could also say that ferrofluids are practically spiking up with unbridled potential!

References

A Brief History of Ferrofluid. (2014, December 23). Retrieved October 12, 2018, from https://www.czferro.com/blog/2014/10/27/history-of-ferrofluids

A. (2015, October 30). The Science Behind Ferrofluids. Retrieved October 12, 2018, from https://www.apexmagnets.com/news-how-tos/the-science-behind-ferrofluids/

Ferrofluid. (2008). Retrieved October 13, 2018, from https://archive.education.mrsec.wisc.edu/background/ferrofluid/index.html

Lockney, D. (n.d.). Magnetic Fluids Deliver Better Speaker Sound Quality. Retrieved October 13, 2018, from https://spinoff.nasa.gov/Spinoff2015/cg_2.html