Fig. 3.
Nanochannel characterizations. (A) Channel width is plotted against master's height for both 10:1 PDMS and 5:1 PDMS. Due to their different elastic moduli, generally 10:1 PDMS nanochannel yields smaller widths than that of 5:1. (B) The nanochannel formation rate is characterized as a function of a/h2, for different elastic moduli (5:1, 10:1, and 15:1) and oxidized vs. non-oxidized PDMS. Each dash line represents the “No collapse,” “Metastable collapse,” “Stable collapse,” and “Annihilation” regions. (C) Schematic representations of four regions in (B). Each region is accompanied with its SEM counterpart. The red arrows indicate the location of the nanochannels (Scale bars, 10 μm).