Directed Assembly of Charged Nanoparticles by Using Electrostatic Forces a Fluidic Medium
Deposition of nanoparticles in a controlled manner is suitable for the application of unique properties of nanoparticles in designing novel electronic devices. Printing different types of particles on the same surface generates multifunctional surfaces and opens up possibilities to celaborate future devices. Electrostatic forces can potentially be utilized to manipulate different types of materials such as magnetic, insulating, conducting, semiconducting, organic and inorganic materials. Moreover, chemistry of materials and the surface is not altered. Herein, we applied these forces to direct and position charged nanoparticles on desired areas of the surface from aqueous dispersions. First, assemblies of single type of particles were obtained on the nano- and microstructured (from 500 nm to 50μm) electrodes by means of electrophoretic forces. The test objects were gold, silver, latex and silica nanoparticles. The next step was to attract two different types charged nanoparticles towards different locations on the same substrate. Last but not least, composite structures were produced with similar technique in order to increase the functionality of the structured surface. To achieve this goal, different types of nanoparticles were coated on top of each other without changing the location of electrodes. The shape of these composite structures was controlled by the electrode geometry.