FIG. 1.

Schematic representation of the microfabrication process. (a) Tungsten wires with controlled change in diameter were generated by etching with partial protection of the wire. (b) Half-etched tungsten wires were inserted into a drill glass slide. (c) Removal of the tungsten wires after PDMS curing created tubes with change in diameter. (d) The PDMS part was removed from the previous glass slide, reservoirs were punched, and the PDMS device was bounded to a glass coverslip by plasma treatment.