  The electrokinetic effect of dielectrophoresis is a promising way of inducing
forces and torques on a broad class of polarizable objects at micro- and
mesoscale. We introduce a non-contact micro-manipulation technique based on
this phenomenon, which is capable to simultaneously position and orient a
micro-object of various shapes. A visual feedback control based on a real-time
optimization-based inversion of a mathematical model is employed. The presented
manipulation approach is demonstrated in a series of experiments with
Tetris-shaped SU-8 micro-objects performed on a chip with a quadrupolar
electrode array. Using more electrodes, the method is readily extensible to
simultaneous manipulation with multiple objects in biology and micro-assembly
applications.
