Motivated by problems posed by biothreat agents, a grand challenge problem for contemporary chemical analysis is the handling and characterization of mass-limited samples. Our approach is to integrate nanometer-scale analytical unit operations into three-dimensional architectures to create integrated fluidic circuits, i.e. structures which handle fluids with the same digital control protocols used by integrated electronic circuits. We are exploring externally controllable interconnects, employing nanocapillary array membranes containing 1-10⁴ nanometer diameter-channels, to produce hybrid three-dimensional fluidic architectures, in which controllable nanofluidic transfer is achieved by controlling applied bias, polarity and density of the immobile nanopore surface charge, and the impedance of the nanopore relative to the microfluidic channels. Such multi-level microfluidic structures are analogous to the massively three-dimensional architectures characteristic of VLSI electronics and open the way for complex arrays of fluidic manipulations to be realized.