  A tool for manipulation of specific nanoparticles is essential for
nanofabrication. This paper describes a new class of nanoscale techniques for
manipulating individual nanoparticles on an insulating substrate using a
focused electron beam. The controlled displacement of 20 nm Au nanoparticles is
demonstrated, along with the extension to other systems, by exploiting the
fundamental principles of particle motion under intense electron irradiation,
which we elucidate. Excitation and ionization by the focused electron beam
within the substrate are shown to produce an electric field on the particle in
this new mechanism. The strength and direction of the electric field, and thus
the motion of the nanoparticle, can be precisely controlled by the current
density, exposure time and position of the electron beam.
