title: Gateable nanofluidic interconnects for multilayered microfluidic separation systems.
abstract: The extension of microfluidic devices to include three-dimensional fluidic networks allows complex fluidic and chemical manipulations but requires innovative methods to interface fluidic layers. Externally controllable interconnects, employing nuclear track-etched polycarbonate membranes containing nanometer-diameter capillaries, are described that produce hybrid three-dimensional fluidic architectures. Controllable nanofluidic transfer is achieved by controlling applied bias, polarity, and density of the immobile nanopore surface charge and the impedance of the nanocapillary array relative to the microfluidic channels. Analyte transport between vertically separated microchannels has three stable transfer levels, corresponding to zero, reverse, and forward bias. The transfer can even depend on the properties of the analyte being transferred such as the molecular size, illustrating the flexible character of the analyte transfer. In a specific analysis implementation, nanochannel array gating is applied to capillary electrophoresis separations, allowing selected separated components to be isolated for further manipulation, thereby opening the way for preparative separations at attomole analyte mass levels.
authors.affiliation: Department of Chemistry, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
authors.forename: Tzu-Chi
authors.initials: TC
authors.lastname: Kuo
authors.forename: Donald M
authors.initials: DM
authors.lastname: Cannon
authors.forename: Yanning
authors.initials: Y
authors.lastname: Chen
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Tulock
authors.forename: Mark A
authors.initials: MA
authors.lastname: Shannon
authors.forename: Jonathan V
authors.initials: JV
authors.lastname: Sweedler
authors.forename: Paul W
authors.initials: PW
authors.lastname: Bohn
mesh_terms: D019075:Electrophoresis, Capillary / Q000295:instrumentation*; D004867:Equipment Design; D008832:Microchemistry / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation; D012212:Rheology