Abstract

A ferrofluid is a magnetic liquid comprised of nanoscale ferrous particles suspended in a low-viscosity carrier fluid. When subjected to a magnetic field, the surface of a ferrofluid will deform into peaks and valleys along the field lines imposed by the magnetic field. The onset of surface deformation is called the Normal Field Instability and a theory describing the NFI identifies a critical magnetic field below which no magnetically driven surface deformations occur. The critical field depends on the state of gravitational acceleration and, according to the theory, should disappear as local gravitational acceleration approaches zero. While there have been previous demonstrations of the Normal Field Instability in a reduced gravity environment, data has been inconclusive on the existence of a critical magnetic field in reduced gravity. For our work, we designed a sounding rocket payload for a suborbital rocket mission. The experiment incorporates a ferrofluid sample and a uniform magnetic field which can be varied across a continuous range of values to observe surface deformations at different applied fields. During the microgravity portion of the rocket’s flight, we obtain video of the ferrofluid’s behavior and compare it to data taken in earth’s gravity. Our experiment is being conducted as part of the Colorado Space Grant Consortium’s Rocksat-C program, and the rocket flight will be carried out in late June at Wallops Flight Facility. A team of 5 undergraduate students designed and built the payload that will characterize the role of gravity in setting the critical magnetic field strength for the onset of the NFI. Data will be used to further understanding of ferrofluid behavior in a microgravity environment to advance its use in various space-based applications.

Supported by the Wisconsin Space Grant Consortium and Concept Zero.