Manipulation of nanoparticles and biomolecules by electric field and surface tension

Electric field has become one of the most widely used tools for manipulating cells, biomolecules, and nanoscale particles in microfiuidic devices. This paper presents the theory, modeling, and experimental works on manipulation of nano and biomaterials by using an electric field and surface tension. Three-dimensional dynamic assembly of nanowires on various microelectrodes under dielectrophoretic force is presented with discussion on capillary action and electroosmosis effects in the manipulation. The various approaches to manipulate the small scale materials are addressed both numerically and experimentally. For successful prediction and analysis on nanoscale, a hierarchical and multiscale scheme for modeling fluid transportation in nanochannels is suggested. The results show that the combined effects of electric field and capillary action induced forces are crucial for precise control over nanoscale materials. (C) 2007 Elsevier B.V. All rights reserved.