INVESTIGATING THE STRUCTURE OF PARAMAGNETIC AGGREGATES FROM
InSPACE-2, and -3), Three Investigations Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions (InSPACE,
Research Area: Complex Fluids
Expedition(s): 6, 7, 12, 13, 16, 18-20, 27-ongoing
Principal Investigator(s): ● Alice P. Gast, PhD, Massachusetts Institute of Technology,
Cambridge, Massachusetts
● Eric M. Furst, PhD, University of Delaware, Newark, Delaware
RESEARCH OBJECTIVES
The Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions (InSPACE)
suite of investigations studies the particle dynamics of magnetorheological (MR) fluids (fluids
that change properties in response to magnetic fields) to help understand adaptable new fluids
for use in such applications as brake systems and robotics.
EARTH BENEFITS
The study of MR fluids on Earth is difficult because
the small magnetic particles remain suspended while
the sediments (large particles) sink. The low-gravity
environment that is provided on the International
Space Station (ISS) will eliminate the effects of
sinking sedimentation. After the magnetic field is
applied to a MR fluid, the microstructures form a
rigid lattice that causes the suspension to stiffen. The
rapid transformation of these fluids without the iron
oxide grains clumping have many possible
technological applications on Earth, especially for
actuator-type devices. This technology has promise
to improve the ability to design structures, such as
bridges and buildings, to better withstand
earthquake damage.
SPACE BENEFITS
At the practical level, these fluids are used in
electromechanical interfaces and devices in which
the fluid is operationally exposed to similar fields that can affect their operation. Current
commercial MR fluid products include tunable dampers and brakes, while future applications in
robotics, clutches, and a host of vibration-control systems are envisioned.
RESULTS
INSPACE (GAST)
Magnetorheological fluids are colloidal suspensions that can form solid-like gels when they are
exposed to a steady, uniform magnetic field. Unique gel structures such as colloid-rich
cylindrical columns can form within the fluid and be maintained by changing the field strength
to relieve any structural stress (Furst 2009).
Video screen shot of the magnetic field that
causes paramagnetic particles suspended
in the fluid to collect into long chains. These
long chains of clumps can interfere with the
emulsions ability to stiffen as it should when
magnetized. This image shows an end view
of the larger aggregates that form during
exposure to a pulsed magnetic field.
Without the settling effects of gravity, the
aggregates grow into complex low-energy
structures. NASA’s Johnson Space Center,
Houston, Texas video.