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Much progress has been made in synthesizing nanoparticles with controlled size, morphology, and crystalline phase during last decade. However, the use of such nanoparticles as a building block to fabricate quantum, photonic or biological nanodevices requires a robust particle positioning on any type of surfaces. A major challenge is faced for developing a general methodology for positioning nanoparticles, which requires a parallel, large area, high resolution, high speed and high flexibility patterning on both conducting and non-conducting surfaces. Recently developed method utilizing electrodynamic focusing of charged aerosols will be discussed in comparison to other positioning methods developed earlier and various nanoarrays consisting of several different nanomaterials on different types of surfaces will be presented. Our method utilizes controlled transport of nanosized charged aerosols under a given electric field. Singly or multiply charged nanoparticles are injected together with the same polarity ions into an electrostatic precipitator chamber where photoresist (PR) prepatterned substrate is located [1]. Ion charges accumulate only on the surface of photoresist for the case of metallic substrate, but, for the case of non-conducting substrate, ion charges accumulate on all surfaces. Charge accumulation for both cases modifies local electric field near the surface generating nanoscopic electrostatic lenses. Charged aerosols are guided and focused through these lenses. In this talk, simulation studies of detailed trajectories of charged nanoparticles will also be presented and the effects of number of particle charges, electric field, and aspect ratio of PR patterns will be discussed. The electrospray technique has been applied to this method for patterning various nanomaterials including gold, polystyrene and protein nanoparticles. Recent findings on how to produce noiseless nanoarrays of various nanomaterials both on metallic and dielectric surfaces will be presented.
[1] H. Kim, J. Kim, H. Yang, J. Suh, T. Kim, B. Han, S. Kim, D.S. Kim, P.V. Pikhitsa and M. Choi (2006) Parallel patterning of nanoparticles via electrodynamic focusing of charged aerosols, Nature Nanotechnology, Vol.1, pp. 117-121
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