title: Nanostructured silicon membranes for control of molecular transport.
abstract: A membrane that allows selective transport of molecular species requires precise engineering on the nanoscale. Membrane permeability can be tuned by controlling the physical structure and surface chemistry of the pores. Here, a combination of electron beam and optical lithography, along with cryogenic deep reactive ion etching, has been used to fabricate silicon membranes that are physically robust, have uniform pore sizes, and are directly integrated into a microfluidic network. Additional reductions in pore size were achieved using plasma enhanced chemical vapor deposition and atomic layer deposition of silicon dioxide to coat membrane surfaces. Cross sectioning of the membranes using focused ion beam milling was used to determine the physical shape of the membrane pores before and after coating. Functional characterization of the membranes was performed by using quantitative fluorescence microscopy to document the transport of molecular species across the membrane.
authors.affiliation: Biosciences Division and Center for Nanophase Materials Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831.
authors.forename: Bernadeta R
authors.initials: BR
authors.lastname: Srijanto
authors.affiliation: Biosciences Division and Center for Nanophase Materials Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831.
authors.forename: Scott T
authors.initials: ST
authors.lastname: Retterer
authors.affiliation: Biosciences Division and Center for Nanophase Materials Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Fowlkes
authors.affiliation: Biosciences Division and Center for Nanophase Materials Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831.
authors.forename: Mitchel J
authors.initials: MJ
authors.lastname: Doktycz