Chemically Functionalized Arrays Comprising Micro and Nano-Electro-Mechanizal Systems for Reliable and Selective Characterization of Tank Waste

Innovative technology of sensory and selective chemical monitoring of hazardous wastes present in storage tanks are of continued importance to the environment. This multifaceted research program exploits the unique characteristics of micro and nano-fabricated cantilever-based, micro-electro-mechanical systems (MEMES) and nano-electro-mechanical systems (NEMS) in chemical sensing

Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste

Our multifaceted research program is aimed at the fundamental and practical development of hybrid micro-electro-mechanical-systems (MEMS) that integrates several elements of chemical selectivity and sensor function. We are developing MEMS sensors that combine chemimechanical transduction, and surface enhanced Raman spectroscopy (SERS) and radiation detection. One of our goals is to develop highly effective methods of immobilizing a wide variety of molecular and ionic recognition phases onto micromechanical surfaces. We have introduced fundamentally new modes of adsorbate-induced surface stress through nano-structuring of microcantilever surfaces; the responsivity for has increased by over two-orders of magnitude over previously existing technological approaches. Noble metal nanostructures similar to those that enhance chemi-mechanical transduction exhibit substantial Raman enhancement factors

Detection and Characterization of Chemicals Present in Tank Waste - Final Report - 09/15/1998 - 09/14/2001

DOE has a strong commitment to the efficient and safe remediation of waste (high level radioactive waste, mixed waste, and hazardous waste) present in underground waste storage tanks. Safety issues arise from the presence of organic chemicals and oxidizers and concerns are raised about the flammability, explosivity, and the possible corrosion of storage tanks due to presence of nitrates and nitrites. Knowledge of the physical parameters and chemical and radioactive composition of waste is necessary for effective and safe tank remediation. New and improved characterization and monitoring of waste present in storage tanks is necessary. The overall goal of this project has been to develop and demonstrate novel multi-parameter micro-electro-mechanical system (MEMS) sensors based on Si and SiNx microcantilever (MC) structures that are robust and can be used to simultaneously detect the presence of target chemicals (analytes) in a mixture, radiation emitted from radioactive materials, an d the heat generated by the absorption of photons of specific wavelength by the target analytes. The mechanisms by which adsorption, photophysical, photothermal processes cause stress in MC surfaces are better understood. Methods of applying a wide variety of chemically selective coatings have been developed specifically for miniaturized MC surfaces, and the response characteristic of the cantilever were shown to be altered dramatically and predictably through incorporation of these phases on the surfaces. By addressing sensitivity and liquid matrix issues, the spectroscopic approach promises to provide an essential element of specificity for integrated sensors. We discovered early in these studies that fundamental limitations exist regarding the degree to which adsorption of analytes on smooth surfaces cause stress and this significantly limits chemi-mechanical response. To circumvent this limitation a concerted effort was made to devise and test ways to nanostructure cantilever surfaces, thereby creating new mechanisms of analyte-induced stress. Substantial improvement in chemi-mechanical response resulted from this work

Capillary electrophoresis techniques in biomedical analysis

© 2015 by Taylor & Francis Group, LLC. Capillary electrophoresis (CE) is a microscale analytical separation technique that has matured rapidly over the past 20 years since the groundbreaking publications of Jorgenson and Lukacs.1,2 Biomedical applications of CE are a leading factor driving the development of what has now evolved into a broad family of related separation techniques. Certainly the most prominent biomedical application of CE is the sequencing of the human genome.3 e accelerated achievement of this goal depended on CE separations.3-5 From 1981 through the writing of this text, more than 14,000 papers were published that included CE and related techniques. A survey of this literature over the past 12 months indicates that more than 70% of these reports include bioanalytical applications of CE