Pressure-driven fluidic delivery through carbon tube bundles.

The aim of this work is to demonstrate controlled flow through macroscopically long (approximately 1 cm) carbon tubes (0.5-1.8 microm in radius). A model, high-throughput, pressure-driven fluidic setup, which features a large number of parallel carbon tubes forming a bundle, is fabricated and tested. The carbon tubes are synthesized and self-assembled via co-electrospinning and subsequent carbonization. The setup accommodates pressure-driven flows with flow discharge rates of the order of 1 nL s(-1) (73 x 10(-11) kg s(-1)) for low-viscosity liquids and 30 nL s(-1) (36.3 x 10(-12) kg s(-1)) for gases into a water pool under imposed pressure drops below 4 bar. The measurements demonstrate the ability to sustain well-controlled laminar flows through these long carbon tube bundles and elucidate the main transport features. A novel procedure is also formulated to recover the flow-carrying tube inner-diameter distribution from the measured dependence of the fluid volumetric or mass flow rate on the imposed pressure drop.