From Nanowerk News: Rowland fellow Fischer devises spiral swimmer nanomachine

Harvard researchers have created a new type of microscopic swimmer: a magnetized spiral that corkscrews through liquids and is able to deliver chemicals and push loads larger than itself.
Though other researchers have created similar devices in the past, Peer Fischer, a junior fellow at the Rowland Institute at Harvard, said the new nano-robot is the only swimmer that can be precisely controlled in solution.
… Fischer and Rowland Institute postdoctoral research associate Ambarish Ghosh were able to control the tiny device well enough to use it to write “R @ H” for “Rowland at Harvard” within a space that’s less than the width of a human hair.