Moses Chan, Director, DMR0213623

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Penn State Center for Nanoscale Science
Moses Chan, Director, DMR-0213623
Nano- and Microscale Motors Powered by Catalytic
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We are investigating micro/nanoscale motors
driven by interfacial tension gradients generated
in catalytic reactions. While catalytically
driven motion on the nanoscale is ubiquitous in
biology, it was previously unknown in artificial
systems. Our first achievement was to make
segmented nanorods with catalysts at one end. In
aqueous hydrogen peroxide we observed directional
autonomous movement up to 9 ?m/sec. By adding
magnetic Ni stripes for steering, we have made
magnetotactic rods that are propelled parallel
to an applied magnetic field. The speed of this
movement is comparable to that of multi-flagellar
bacteria, such as bacillus cereus). We have also
demonstrated controlled rotational movement of a
free gear measuring 100 ?m in diameter using
interfacial tension gradients, and are developing
microfluidic pumps based on catalytically driven
movement of fluids over patterned surfaces.
Real-time video of catalyzed motion Au-Pt
nanorods in hydrogen peroxide solution

• W. Paxton et al., J. Am. Chem. Soc. 2004, 126,
  13424.
• T. Kline et al., Angew. Chem. Int. Ed. Engl., in
  press.
• J. Catchmark, et al., Small, in press.

A fabricated Au gear with Pt catalysts on the
gear teeth.