Strategies for Controlled Placement of Nanoscale Building Blocks

The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others

Titanium-based dielectrophoresis devices for microfluidic applications

To date, materials selection in microfluidics has been restricted to conventional micromechanical materials systems such as silicon, glass, and various polymers. Metallic materials offer a number of potential advantages for microfluidic applications, including high fracture toughness, thermal stability, and solvent resistance. However, their exploitation in such applications has been limited. In this work, we present the application of recently developed titanium micromachining and multilayer lamination techniques for the fabrication of dielectrophoresis devices for microfluidic particle manipulation. Two device designs are presented, one with interdigitated planar electrodes defined on the floor of the flow channel, and the other with electrodes embedded within the channel wall. Using these devices, two-frequency particle separation and Z-dimensional flow visualization of the dielectrophoresis phenomena are demonstrated