Large DNA molecules assume extended conformations upon their insertion into nanofluidic channels.  This confinement-induced extension can be used to increase the spatial resolution with which the molecule can be sized, probe locations mapped, or nucleotide sequence decoded.  Greater extension, and spatial resolution, can be achieved by decreasing the critical dimensions (width and depth) of nanochannels.  This, however, imposes stricter requirements on fabrication methods and creates new challenges for device operation.  For example, as nanochannel dimensions decrease, the entropic barrier to DNA threading into the channels increases.  As a result, larger applied forces (e.g., pressure or electrostatic) are required to drive DNA threading into and transport through nanochannels and faster DNA transport is observed.  This makes characterization of the confined DNA difficult when using detection methods having limited bandwidth or sensitivity.  In order to maximize control over both DNA extension and transport velocity, fluidic devices are required that allow greater control over transport dynamics.  We report on the development and operation of devices with components such as three-dimensional nanofunnels.  The use of such structures lowers the threshold force needed to drive transport and thus provides greater control over transport dynamics.  It is therefore possible to characterize a molecule when it first enters a nanochannel and trigger a command to the device.  With electrokinetically-driven DNA transport, for example, the molecule can be sorted or its transport halted, slowed, or reversed by adjusting the on-chip voltages.  We also report on the development of an all-fluidic device for the detection of DNA during its transport through a nanochannel.  This is achieved by intersecting a long transport channel with a shorter orthogonal nanochannel. The ionic conductance of this transverse nanochannel is monitored while DNA is electrokinetically driven through the transport channel. When DNA passes the intersection, the transverse conductance is altered, resulting in a transient current response.