Magnetic Fluids
A ferrofluid on a reflective glass plate under the influence of a strong magnet underneath.Copyright 2006 Gregory F. Maxwell (left) and 2008 Opoterser (right) http://commons.wikimedia.org/wiki/File:Ferrofluid_Magnet_under_glass_edit.jpg http://commons.wikimedia.org/wiki/File:Ferrofluid_close.jpg
In this fun, engaging activity, students are introduced to a unique type of fluid—ferrofluids—whose shape can be influenced by magnetic fields! Students act as materials engineers and create their own ferrofluids. They are challenged to make magnetic ink out of ferrofluids and test their creations to see if they work. Concurrently, they learn more about magnetism, surfactants and nanotechnology. As they observe fluid properties as a standalone-fluid and under an imposed magnetic field, they come to understand the components of ferrofluids and their functionality.
Around since the 1960s, ferrofluids have been used as audio speaker coolants and high-end engineering seals. Dynamic rotary shaft seals are an example of high-end sealing technologies that are typically implemented by mechanical engineers in an industrial plant setting. Recently, this technology has been a topic of research involving nanoparticle suspensions and engineering design so they have greater magnetic properties under moderate magnetic fields. Materials engineers have developed new nanomaterials for medical applications targeted towards localized drug delivery systems by induced magnetic fields. Materials engineers use basic chemistry and physics fundamentals as well as newly acquired nanoscience concepts to introduce particles small enough to transport through capillary systems and organs and have sufficient magnetization. Additionally, materials and biochemical engineers design biocompatible and biodegradable organic coatings that reduce toxicity levels and biochemical reactions that may occur with magnetic nanomaterials inside human or animal bodies. Most importantly, the fluid must behave like a fluid until a magnetic field is applied.
After this activity, students should be able to:
- Explain magnetism theory.
- Describe the role of each ferrofluid ingredient.
- Describe the unique behavior of ferrofluids under the influence of magnetic fields.
- Describe applications and uses for ferrofluids.