KTH/KI Nano- and Microtechnology Centre invites you to a presentation
in a series of seminars related to Nano- and Microtechnology
The Nanoscience and Nanotechnology of Magnetic Liquids (Ferrofluids)
Professor Markus Zahn
Massachusetts Institute of Technology, Boston, USA
Lab for Electromagnetic and Electronic Systems
Dept Electrical Engineering & Computer Sciences
Place: Lecturehall B2 at Department of Materials and Engineering, Brinellvägen 23
Date: January 21, 2005 15.15 - 17.00
Between 16.30 - 17 there is time for discussion. Beer/juice with sandwich will be served.
(The latter requires advance announcement of participation, before Jan 19, to Larsm@iip.kth.se)
For abstract and information about Prof. Zahn, see below
Welcome!
Lars Mattsson / Mamoun Muhammed
KTH/KI Nano- and Microtechnology Centre
c/o Lars Mattsson, IIP, Brinellv. 68, SE-100 44 Stockholm, http://www.micronano.kth.se/
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ABSTRACT
From their invention in the mid 1960s, ferrofluids involved nanoscience and nanotechology
because they consist of ~10 nm diameter magnetic nanoparticles coated with a 1-2 nm thick layer of
surfactant to prevent agglomeration by steric hindrance and electrostatic repulsion. The coated
nanoparticle is dispersed in a non-magnetic carrier liquid, typically water or oil, to form a stable
colloidal suspension and unlike the more concentrated and larger magnetic particles in
magnetorheological (MR) fluids, ferrofluids maintain fluidity even in intense magnetic fields.
Magnetic nanoparticles and ferrofluids can be used in magnetic field based micro/nanoelectromechanical system (MEMS/NEMS) sensors, actuators, and fluidic devices and offer advantages
over analogous electric field devices with stronger forces and increased reliability as there are no
catastrophic failure mechanisms analogous to electrical breakdown. Magnetic nanoparticles can bind
to drugs, proteins, enzymes, antibodies, or organisms and can be directed to an organ, tissue, or tumor
using an external magnet or can be heated in alternating magnetic fields for use in hyperthermia.
This seminar will describe the integrated chemistry, fluid mechanics, and magnetic
nanoscience and nanotechnology of magnetic nanoparticles and fluids with summary reviews of
ferrofluid synthesis: composition, colloidal stability, and preparation; ferrofluid magnetization:
relaxation time constants and Langevin magnetization characteristic; ferrohydrodynamics: Bernoulli’s
law of pressure and flow, instabilities, and rotating magnetic field torque driven phenomona;
applications to micro/nano-electromechanical systems: magnetic particle sensors, actuators, and
microfluidic devices; and bionanosensors. Videos of new ferrofluid phenomena in rotating magnetic
fields will show spiral flows, abrupt transitions from a single large drop to many smaller droplets, and
traveling wave pumping of ferrofluids.
Prof. Markus Zahn
Markus Zahn is the Thomas and Gerd Perkins Professor
of Electrical Engineering at MIT and Director of the VIA Internship Program, a cooperative work/study program
with industry. He received all his education at MIT in
the Department of Electrical Engineering from 1964-70,
receiving simultaneous BSEE and MSEE degrees in
1968, an Electrical Engineers degree in 1969, and a
Doctorate of Science in 1970. He then became a
professor in the Department of Electrical Engineering at
the University of Florida, Gainesville until 1980,
including a sabbatical at MIT in 1976-77. He joined the
MIT faculty in 1980 and works in the Laboratory for
Electromagnetic and Electronic Systems and in the MIT High Voltage Research Laboratory where he does
research on electromagnetic field interactions with materials and devices.
He is the author of ELECTROMAGNETIC FIELD THEORY: A Problem Solving Approach and has codeveloped a set of educational videotapes on Demonstrations of Electromagnetic Fields and Energy. He is
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co-inventor on patents for elimination of parasitic currents in batteries; a fluid stabilization method using
magnetic fluids so that a less viscous fluid can stably push a more viscous fluid; an instrument for
measurement of charge entrained in fluids; a process for magnetic media milling; a magnetometer and
dielectrometer for detection, identification and discrimination of metallic and non-metallic buried objects
such as landmines; the optimization, calibration, and display of dielectrometry signals; for field assisted
ion mobility spectrometry; for a detection array for buried objects such as landmines; and a method for
magnetically assisted assembly of integrated circuit wafers. His fields of research and interest include
electro-optical field and charge mapping measurements; high-voltage charge transport and breakdown
phenomena in dielectrics; flow electrification phenomena in electric power apparatus; development of
capacitive and inductive sensors for measuring profiles of dielectric, conduction, and magnetic properties
of media as well as related physical properties such as moisture profiles; electrohydrodynamic and
electrokinetic interactions with charged and polarizable fluids; ferrohydrodynamic interactions with
magnetizable fluids; continuum electromechanics of electrofluidized and magnetically stabilized beds;
magnetic diffusion phenomena and forces in MAGLEV systems; and magnetic field devices for micro
and nanoelectromechanical system (MEMS/NEMS) applications. He is also developing web based
demonstrations and animations for the enriched teaching of electromagnetism.
He has received numerous awards for excellence in teaching, including the MIT Graduate Student
Council Teaching Award in 1989 and the MIT Frank E. Perkins award for excellence in graduate student
advising in 1999. He has been very active in IEEE Dielectrics and Electrical Insulation Society activities
and conferences, presently serving as an Associate Editor of the Transactions and Chairman of the Liquid
Dielectrics Committee.
He is a Fellow of the IEEE for "contributions to the understanding of the effects of space charge and flow
electrification on the conduction and breakdown properties of dielectrics"; was the 1998 J.B. Whitehead
Memorial Lecturer of the Conference on Electrical Insulation and Dielectric Phenomena with a published
lecture entitled: "Optical, Electrical, and Electromechanical Measurement Methodologies of Field,
Charge, and Polarization in Dielectrics" [IEEE Transactions on Dielectrics and Electrical Insulation, Vol.
5, No. 5, October, 1998, pp.627-650]; the First James R. Melcher Memorial Lecturer (2003); and with
MIT EECS student Cory Lorenz ('03) was one of the winners of the November, 2002 American Physical
Society Division of Fluid Dynamics Gallery of Fluid Motion with video entitled "Hele-Shaw
Ferrodydrodynamics for Rotating and Axial Magnetic Fields."
He serves on the Academic Advisory Board of the W.M. Keck Laboratory for Electro-Hydrodynamics of
Suspensions at the New Jersey Institute of Technology and was a member of the National Academies
Naval Studies Board Committee for Mine Warfare Assessment in 2000-2001. He is also a co-author of
the committee report "Naval Mine Warfare, Operational and Technical Challenges for Naval Forces,"
National Academy Press, Washington, DC, 2001. Prof. Zahn was a member of the MIT Humanitarian
Demining Group and successfully completed the Deminers Orientation Course at the Night Vision and
Electronic Sensors Directorate Countermine Division at Ft. Belvoir, Virginia in 1998.