Magnetic micro-machines capable of swimming through liquid or gel were fabr
icated. The micro-machines were driven by an external rotating magnetic fie
ld and featured a screw-shaped structure and permanent magnet. The machines
could swim under condition of a Reynolds number (Re) of 10(-7) and were ab
le to run through agar or a bovine tissue sample using the same principle.
Their running behavior was dependent on the frequency and strength of the e
xternal field, and on the surrounding media. These machines have great pote
ntial for medical applications in the human body. (C) 2001 Elsevier Science
B.V. All rights reserved.