Magnetic nanorods on cruise control

Chemists have created miniature engines out of nanoscale metallic rods that propel themselves using chemical energy. The technology might one day yield new kinds of sensors or even tiny machinery for assembling nanodevices.

Each rod, about 1.5 micrometers long and 400 nanometers wide, consists of multiple segments of platinum, nickel, and gold. When the filaments’ makers at Pennsylvania State University in State College added them to an aqueous solution of hydrogen peroxide, the platinum segment, located at one end of the rod, broke down the hydrogen peroxide, releasing oxygen.