University of California
San Diego

Departments of Nanoengineering
and Bioengineering

 

Sara Zare

 

Current Research

Separating bacteria and viruses from undiluted blood using Dielectrophoresis

Electric field guided nanowires: a new approach for nanofabrication

Gold-Platinum (Au-Pt) nanowires will provide an extraordinary opportunity for carrying out complex biochemical and biomolecular tasks in the future. The Au-Pt components of nanowires undergo oxidation–reduction reactions when hydrogen-peroxide is introduced to the system as fuel, hence the name nanomotor. The oxidation–reduction reactions provide propulsion for moving through a fluidic milieu. It has been shown that nanomotors also have the capability to transport cargo to specific location. Precise steering of nanomotors will be required to carry out complex bioreactions. To date, magnetic field steering has been the major focus for nanomotor researchers. However, to make nanomotors responsive to magnetic fields, presence of a magnetic component (i.e. Nickel) in nanomotor structure is essential. The ultimate goal of this project is to bring the nanomotor controlled steering and task performance capabilities to the next level. This advancement could introduce the next generation nanomotor microfluidic system that actively delivers reactant molecules to the reaction chamber. It also facilitates the 3D nanoassembly of nanomotors. Taking advantage of precise electrical steering, which creates a more biocompatible milieu for biomolecules in microfluidic systems on the one hand, and the presence of some degree of electric charge on most biomolecules surface on the other hand, makes electric field steering of nanomotors considerably more desirable (omitting the need for any magnetic component in the environment.) In our initial work we have shown that nanomotors movement can be controlled through the application of heat and electric fields. The electric steering not only minimizes complications in microfluidic system design (need for microfluidic pumps), but may also overcome the microfluidic surface adhesion problem. We are postulating that incorporating existing microelectrode array technology is going to allow electric fields to be used as steering mechanism for nanomotors. We also believe that by controlling the voltage and number of active microelectrodes it will be possible to have precise control of speed, steering direction and positioning. Implying correct amount of current or potential will also introduce a breaking function to nanomotors. It will also overcome the biocompatibility concerns. In addition to all these advantages, it may facilitate the 3D nanoassembly of nanomotors.