Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

   

2009 Research Summary

Generic Nanomaterial Positioning by Carrier and Stationary Phase Design

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Ali Javey, Roie Yerushalmi, Johnny Ho and Zachery Jacobson

We have developed a generic approach for deploying various types of synthetic nanomaterials, including SWNTs and nanoparticles, at well-defined locations on substrates. The assembly is achieved through the complementary design of the stationary and carrier phases, and utilizes the dewetting process during which polymer based "shuttles" deliver and position the nanomaterials on predefined locations on substrates. Covalent modification of the nano-objects is not required for the building block positioning, therefore preserving their intrinsic chemical and physical properties. The potency of this new approach is demonstrated for various synthetic nanomaterials, such as polystyrene, silica, and gold nanoparticles as well as single-walled carbon nanotubes, showing highly specific and direct patterning of cm2 areas using a generic assembly strategy.

Figure 1
Figure 1: Si/SiO2 substrate is chemically modified with fluoro-terminated and hydroxyl-terminated regions that serve as the stationary phase. After the dewetting process, the nano objects from the carrier phase are directly and selectively assembled on hydroxyl-terminated regions while leaving the fluoro-terminated regions blank. To achieve the dewetting process, the carrier phase containing the nanomaterials and the polymer-based "shuttles" is swiftly retracted by a pipette from a vial until the liquid level drops below the surface of the substrate.

[1]
Nano Letters, Vol. 7, 2007, pp. 2764-2768.