Movement of magnetic bacteria in time-varying magnetic fields

The magnetic moment of individual living magnetic bacteria was determined by motion analysis in a time-dependent magnetic field. For this purpose we had to estimate the drag exerted on the moving bacterium by the surrounding liquid. First, the bacterium was approximated by an ellipsoid. In order to determine drag coefficients for more complicated (and realistic) forms, a model experiment was built. In this experiment enlarged models of bacteria were rotated in a viscous liquid and the torque acting upon them was measured. Computing algorithms were developed in order to calculate drag coefficients of magnetic bacteria and to simulate their motion in magnetic fields. The experimental and numerical determination of the drag coefficients agree within their error bounds. Besides the determination by motion analysis, the bacterial magnetic moment was also calculated from the number and size of magnetic particles contained in the bacterium as seen in an electron microscope. The results of both calculations agree well.

@article{id105,
  author = {Steinberger, B. and Petersen, N. and Petermann, H. and Weiss, D.},
  journal = {J. Fluid Mechanics},
  language = {en},
  pages = {189-211},
  title = {Movement of magnetic bacteria in time-varying magnetic fields},
  volume = {213},
  year = {1994},
}

%O Journal Article
%A Steinberger, B.
%A Petersen, N.
%A Petermann, H.
%A Weiss, D.
%J J. Fluid Mechanics
%G en
%P 189-211
%T Movement of magnetic bacteria in time-varying magnetic fields
%V 213
%D 1994