Controlled and localized Au-TTF micro- and nanowire formation by diffusion of the precursors through PDMS

Abstract

Here, we demonstrate the well-defined and site-specific synthesis of few or single conductive goldtetrathiafulvalene (Au-TTF) micro- and nanowires. The microfluidic device consists of two separate channel systems, one of which is filled with HAuCl4, the other one with tetrathiafulvalene, both in organic solvents. The organic solvent causes swelling of PDMS thereby enabling diffusion of TTF through PDMS into the adjacent channel with HAuCl4, where the redox reaction is induced. The enhanced control over reaction parameters and the shear stress-free environment allows the reproducible formation of extraordinary long wires with diameters of below 2 μm and lengths up to 1 mm.