Back in the early 1960s, a fledgling NASA was presented with lots of new problems. Going to space was unlike anything humans had ever done, and engineers and scientists were constantly searching for answers to issues they had never even considered before.
One of these problems was dealing with the properties of a liquid in low-gravity environments. On Earth, a liquid will stay at the bottom of its containers as gravity pulls it down. But without gravity, the liquid will float all around its container, forming spheres of liquid.
Since the rockets used by NASA relied on liquid fuel, there was a problem getting the fuel pumped to the engines once the spacecraft was in orbit. Several ideas were tried, and though NASA eventually settled on small solid rockets to settle the liquid fuel near the intake, one of the ideas proposed by a scientist named Steve Papell was a ferrofluid fuel.
A ferrofluid is any liquid with metallic metal suspended in it. The metal has a special material coating to prevent the small pieces from attracting or repelling each other, but when the solution is exposed to an exterior magnetic field, the ferrofluid is attracted to the magnet. It also increases in density and becomes somewhat rigid.
When Steve Papell suggested using a magnetic fuel, his idea would be to control the flow of the fuel by using magnets. Instead of letting the
liquid blob in the center of the tank, it could now be held towards the fuel intake and make the system more efficient. Though it was a good idea, NASA found other, better solutions for the rocket issue.
That didn’t mean the end of ferrofluids, however. Another scientist named R.E.Rosensweig improved upon the design and developed a new branch of fluid dynamics known as ferrohydrodynamics.
Since then, ferrofluids have been used in many devices — the most common of which is in electronic devices such as hard disks, using it to form liquid seal that will be held in place by magnets. This seal prevents dust and other materials from entering the hard drive.
Despite its practical uses, ferrofluid is just cool to look at. If you ever have the chance, grab a magnet and play around with it!
Written By: Scott Yarbrough