Gold nanoparticles, 10 to 15 nm in diameter, were directly delivered to a silicon oxide substrate. The particles were immobilized via electrostatic interactions to the silicon dioxide surface by modifying it to be positively charged.

Various nanoparticles were directly patterned using the NFP. Gold nanoparticles, diamond nanoparticles, DNA, multiple thiols. Nanometer-scale dot and line features were fabricated with a sub-100 nm resolution. The same fountain probe could be used continuously to deposit particles for over 40 minutes, with repeatable results. NFP technology is therefore poised to impact applications based on the manufacturing of conductive nanowires,metallic structures or bioassays.

Publications 

• K.-H. Kim, R.G. Sanedrin, A.M. Ho, S.W. Lee, N. Moldovan, C.A. Mirkin, and H.D. Espinosa. "Direct Delivery and Submicrometer Patterning of DNA by a Nanofountain Probe," Advanced Materials, VOl. 20, No. 2, p. 330-334, 2008.
• B. Wu, A. Ho, N. Moldovan, H.D. Espinosa, "Direct Deposition and Assembly of Gold Colloidal Particles Using a Nanofountain Probe", Langmuir, Vol. 23, No. 17, p. 9120-9123, 2007.
• N. Moldovan, K-H. Kim, and H.D. Espinosa. "Multi-Ink Linear Array of Nanofountain Probes," Journal of Micromechanics and Microengineering, Vol. 16, No. 10, p. 1935-1942, 2006.