MRI: Development of an Electron-Beam based Instrument to Study Nanoscale Processes in Liquids

The proposed development effort seeks to design, construct, and validate an electron-beam based instrument that can be used both to induce and to study nanoscale chemical and physical processes in bulk liquids. In addition to performing electron-microscopy in liquids, the proposed instrument will enable direct electron-beam based fabrication using liquid reactants while allowing one to spectroscopically analyze the corresponding radiochemical reactions and fabricated nanostructures. Moreover, the system will enable the study of both nanoscale fluid transport and nanoscale functional materials in operational environments with the added capability to modify those environments using electron-beam induced processes. The nanoscale fabrication capabilities are based on a novel technique, developed in the PI’s laboratory,[1-5] in which a focused electron beam deposits or etches materials by inducing localized chemical reactions in bulk liquids. The technique has many advantages over electron-beam induced processing using gas-phase reactants including much higher material purity, access to new materials, faster processing rates, ability to work with insulating substrates, and use of low cost, stable, low-toxicity reagents. In situ microspectroscopy in the UV-VIS-NIR and x-ray regimes will permit real-time characterization of both the chemical reactions and the deposited nanostructures. This unique instrument will immediately impact a range of nanoscale science and engineering research efforts encompassing photonics, electronics, magnetics, energy storage, and fludics in addition to enabling fundamental studies of electron-beam induced reactions in liquids. Intellectual Merit: The proposed instrument advances knowledge in the primary field of electronbeam induced processing by providing a unique tool with which to study e-beam driven deposition and etching reactions in liquids. Traditional e-beam induced processing with gaseous reactants has had limited impact because is typically produces highly contaminated materials. In contrast, many of the investigations discussed here are only possible because of the high purity of liquid-phase processes. The new instrument will also advance understanding in the wide ranging fields of nanoscale photonics (plasmonics and quantum dots), electronics (graphene and semiconductor nanostructures), magnetics (spin-based devices and patterned magnetic structures), fluidics (in situ electrokinetics), and energy storage (in situ studies of battery electrodes). In addition, it brings a new perspective and capability to radiation chemistry by providing a means to studying radiochemical reactions in nanoscale volumes and at solid-liquid interfaces. The assembled team is well suited to the development effort with broad experience in electron-beam, microfluidic, and material analysis instrumentation as well as the related nanoscale science and engineering fields. Broader Impacts: Overall the development of a new approach and a new instrument for studying nanoscale processes in liquids will accelerate the scientific and engineering community’s efforts to bring nanotechnology to bear on pressing societal problems. For example, specific research projects enabled by this instrument target medical diagnosis, environmental monitoring, energy production and storage, and information technology. The effort is also well integrated with educational and outreach efforts at the University of Kentucky. Even before the instrument is commissioned, plans are in place to make the tool available to both NSF REU site participants and engineering senior design teams for rapid exploration of new device and materials concepts. The U.K. Electrical and Computer Engineering REU site program recruits students almost exclusively from underrepresented groups. In addition, ongoing programs within the University of Kentucky Center for Nanoscale Science and Engineering (CeNSE) and the Center for Advanced Materials (CAM) will integrate the instrument into activities which often reach underrepresented students from Kentucky’s Appalachian region. The instrument development plan also enhances research ties between nanoscale science and engineering programs at the University of Kentucky and the University of Louisville. Finally, this focused development effort provides the opportunity not only to disseminate the research outcomes, but also to make the instrument design available to other laboratories through both rapid (web-based) and archival (journal-based) means.