Remote manipulation of micronanomachines containing magnetic nanoparticles.

We report remote manipulation of micronanomachines containing magnetic nanoparticles. Surface-modified Fe(3)O(4) nanocrystals were synthesized as doping agents of the photopolymerizable resin, which was pinpoint written by femtosecond laser-induced two-photon photopolymerization to create microsprings. Owing to the nature of superparamagnetism of Fe(3)O(4) nanoparticles, force exerted to the microsprings relies sensitively on the field gradient of the external ferromagnet, and various motions like elongation, bending, and swing are achieved in a well-controllable remote manner. As a noncontact, sensitive, easy, and environmentally friendly approach, the magnetic driving of micronanomachines may play an important role for nano and biological applications.