Download or read book Transport Processes in Free Surface Microfluidics written by Brian Douglas Piorek and published by . This book was released on 2008 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted to examine the dominant fluid transport physics at the macro, micro, and molecular scale. Three novel techniques were developed to elucidate the fluid flow fields occurring in microscale and nanoscale fluidic systems. These techniques were then used to design and investigate a novel free-surface microfluidic system capable of delivering sustained and controlled flows ranging from 0 -- 1000 mum/s. The microsystem was then used to develop a sensitive and selective chemical detector capable of identifying certain gas-phase molecules present in the nearby atmosphere. The detector performs molecular recognition of gaseous compounds in the adjacent atmosphere by surface enhanced Raman spectroscopy and the transport properties of the microfluidic system are designed to maximize vapor detection capability. Chemical detection sensitivity of gaseous compounds is better than PPT. Vapors emanated from some nearby solid compounds are also detected at room temperature, including the gas-phase molecules naturally emitted from the explosive compounds: TNT, TATP, picric acid, RDX; and from narcotic samples such as cocaine.