Fundamental Electromagnetic Configuration for Generating One-Directional Magnetic Field Gradients

In this article, electromagnet layouts are presented, which generate a magnetic field with a magnitude gradient that does not vary significantly in a horizontal plane but decreases monotonically with the vertical height above the magnet. Such a one-direction magnetic field gradient is a specific requirement for magnetic density separation ...

A compact low-cost XY360° stage: using Arduino and PWM based amplifiers

The application of actively controlled micrometer precision positioning stages in products that are accessible to start-ups, individual consumers or third world countries is currently limited by their price and size. To solve this problem, the use of low-cost and compact components in stages is investigated. Earlier research done in the MSD...

Designs for rotary shaft fluid seals in an aqueous environment using fer- rofluid

Seals are used throughout the technology spectrum to prevent products form leaving their container or preventing foreign products to enter. With the sealing of rotary parts like shafts the seal needs to not only provide sealing capabilities, but also simultaneously allow for the desired movement without too much friction or wear. This is often...

Validation of the in-plane friction behaviour of a ferrofluid bearing

The repeatability of precision positioning systems can be improved by reducing the effects of stick-slip in the system. Stick-slip effects introduce a spontaneous jerking motion when overcoming the static friction coefficient, creating accelerations that are hard to predict. Contactless bearing types, such as magnetic levitation or fluid...

Rheology of a ferrofluid and magnetorheological fluid in a magnetic field

Through flow experiments, we determined the rheological properties of both a ferrofluid and a magnetorheological fluid. These rheological properties were affected by the presence of an external, variable, magnetic field. The rheology of the ferrofluid was almost unaffected by the magnetic field. The rheology of the MRF was strongly affected by...