Imagine a dark liquid that instantly develops pointed spikes as soon as you place a magnet nearby. It is ferrofluid, and its movement looks pretty natural. The following article will give you a detailed explanation of the substance, its functioning, demonstrations in a safe classroom, and its presence in real life.

What Is Ferrofluid?

Ferrofluid, as the name suggests, is a fluid made of iron; therefore, it has magnetic properties. These properties are due to the presence of nano-sized magnetizable particles dispersed in oil or water. If you put a magnet next to it, the fluid reacts straightaway, creating spectacular spikes following the magnetic field. The particles are so tiny that they do not settle; instead, they remain mixed. A good analogy is that it resembles liquid metal, flowing under the influence of magnetic forces.

How It Works

Inside the fluid, the tiny particles are all magnetized. When a magnet is near, they orient themselves in the direction of the magnetic field, which is not visible. It is the combination of surface tension and magnetism that results in those typical spike formations. Thermal energy is also acting on the particles, which is why, in the end, instead of clumping, the fluid remains liquid as the particles are always on the move.

Classroom Demos and Quick Activities

Teachers have the option to change the characteristics of these activities for various grade levels.

• The Magnet vs. ferrofluid demos can be conducted as a teacher-led demonstration. Take a small amount and place it in a transparent container. Position a powerful magnet under it. Observe that the liquid suddenly creates spikes.

• Pattern exploration offers the opportunity for small groups to participate hands-on. Pour a certain quantity of the substance into a shallow dish. Move a bar magnet underneath to see the field lines.

• Measuring and sketching are activities for older students. They draw patterns of spikes for different magnet strengths, then give a short description.

Safety and Handling

• Always use gloves because this fluid stains

• Store it in a place away from electronics and small children

• Purchase only from recognized suppliers that offer classroom-safe kits

Real-World Uses

As a unique substance, it is not just a demo material. Engineers use it as a seal in computer hard disk drives. It also appears in magnetic sensors. Moreover, it is an essential component in the art world for creating amazing visual presentations.

Bringing Science to Life

Magnetic fluid is not only applicable in the teaching of magnetism but also in the teaching of observation through one exceptional demonstration. The students will never forget the lesson that was presented in such a dramatic way. 

Geyer Instructional has been providing schools with science kits and STEM tools since 1960. Teachers can also find classroom-safe ferrofluid kits that make this experiment accessible. Visit Geyer Instructional to see what is available for your next lesson.