Ferrofluid

Ferrofluid, also known as magnetic fluid, is a liquid that becomes magnetized in the presence of a magnetic field.
It consists of tiny magnetic particles, typically iron oxide, suspended in a base liquid (carrier fluid) and stabilized with a surfactant to prevent clumping.
In the absence of a magnetic field, it behaves like a regular liquid. However, when exposed to a magnetic field, the particles align to become temporarily magnetized.
Once the magnetic field is removed, the fluid loses its magnetization, showing no residual magnetization or hysteresis.
Ferrofluids are used in various fields such as mechanical engineering, electronics, and medicine, where their unique magnetic properties are used for damping, sealing, and imaging purposes.
Please refer to this page for technical information about ferrofluid.

Configuration diagram of magnetic fluid

The history of Ferrofluids dates back to the early 1960s when they were developed for NASA's space program to enable the transfer of liquid fuel in zero-gravity environments. Capitalizing on their magnetic responsiveness, ferrofluids have since been utilized in various industrial applications.

Ferrofluids have numerous applications, with one of the most common being in audio speakers and smartphone components.
In speakers, they provide damping, heat dissipation, and centering effects.
Similarly, In Ferrofluids used in smartphones linear vibration motors and wearable devices, damping effects can be expected.
Ferrofluids are also used in components for semiconductor manufacturing equipment. In semiconductor production, maintaining a vacuum environment is crucial. Ferrofluids act as sealing materials within vacuum seals, enabling power transmission in that environment.
Additionally, ferrofluids are used in various other applications, each with its own unique benefits: