Elliptically-Polarized-Surface-Wave-Scattering-Based Diagnosis of Self-Assembly and Nano-Fabrication

Intellectual Merit The reliable control of nanoparticle growth and surface assembly is a key building block to nano- technology. Such a control requires advanced diagnostics approach which allow real-time, on-line detection and characterization of self-assembly and nano-fabrication. Applications of such a diagnostic tool will be numerous, and will include electronics, bulk material fabrication, membrane synthesis, nano- mechanical systems, and DNA screening. In particular, we anticipate the use of this approach for the growth of highly aligned CNT-based membrane structure for highly-selective chemical separations in near-term application. Here, a novel experimental diagnostic tool is proposed to characterize self-assembly of nano-size particles and structures via elliptically-polarized surface-wave scattering (EPSWS). With this approach, the self assembly of nano particles on a surface can be monitored while the solution chemistry is altered for optimal particle dispersion without agglomeration, making the approach a poweful on-line diagnostic tool. The technique can eventually be used for real time feedback control of self-assembled nanostructures, and will provide a much less expensive alternative to the traditional, ex-situ, SEM, TEM, and AFM measurements. This diagnostic approach is based on the measurements of angularly-resolved scattered surface waves, which make it quite different than the traditional light scattering techniques. By nature, the surface waves are more sensitive to the particles and objects near a surface (thin metallic film), and therefore allow the detection of nano-size (5-10 nm in diameter) particles beyond the capability of traditional elastic light scattering approaches. Theoretical results and comparisons with limited data available in the literature show the high success potential of the EPSWS methodology. During this project, a system will be built and tested to demonstrate the capability of this new diagnostic modality. Broader impact of the proposed activity We expect that the proposed diagnostic tool is likely to be an important and integral part of many nano-fabrication techniques, which are projected to grow significantly over the next several decades. It will have an indirect impact on the society at large, as it will be instrumental in reducing the costs and improving the reliability of nanomaterials-based devices, tools and manufacturing applications. During the proposed activity, we will have two undergraduate students working on different aspects of the EPSWS-concept development. They will be part of the new Nano-Engineering Certificate Program established at the University of Kentucky, and their education will be enhanced by the broad scope of research topics covered, including self-assembly chemistry, thin-film applications, chemical separations, micro-fabrication techniques, advanced optics, and microscopic characterization techniques. In addition, they will closely interact and benefit from the daily scholarly discussions with the two professors and the senior research associate of the interdisciplinary team. This novel multidisciplinary research effort will provide career opportunities to students, both from general as well as underrepresented groups. We will announce the opportunities to women and minority engineering students, and encourage them to take part in our research and development activities. In addition, we will discuss our research with the area high school students, which is part of our commitment to the Nano-Engineering Certificate Program. Potential success in recruiting the best high school students, as well as the women and minority undergraduate engineering students to our group will help us to increase the numbers of students choosing careers in science/engineering, particularly related to nano- technology applications.