ABSTRACT
This chapter examines the use of microelectrode structures — quadrupoles, castellated electrodes, interdigitated traveling wave arrays, dielectrophoretic ratchets — and their applications for the manipulation of nanoparticles. A range of microfabrication techniques exists for the construction of electrode structures, but the principal method employed is that of photolithography. For the majority of cases where a single electrode layer is required, wet etching is the simplest and most effective procedure. The significant difference between wet and dry etching comes about because the ions are charged, and hence respond to an applied electric field. Another anisotropic etching technique, which can be applied equally for removal of metal for electrode fabrication, and to other materials for channel or via hole formation, is laser ablation. However, the development of microengineered electrodes, laboratories on a chip, and so forth are all new developments, and as such the existing patent literature must be considered when developing commercial devices.
