Fig. 5.

Interfacing nanofluidics with microfluidics and demonstration of a nanofluidic concentration device. (A) The nanofluidic concentration system used here consists of two functionally interfaced channels: A micrometer scale channel fabricated from a double thickness master and two nanoscale channels fabricated from the collapse of a single layer thickness master. Schematic representation of the operation of the device shows the concentration of nanoparticles at the interface between the microchannel and the nanochannel. (B) SEM images of (1–2) the nanofluidic channel (400 nm width × 300 nm height) and (3) microfluidic channel (10 μm width × 1.4 μm height). (C) Time-lapse images of concentration of 700-nm polystyrene nanoparticles at the interface between microchannel and nanochannel.