Integration and characterization of solid wall electrodes in microfluidic devices fabricated in a single photolithography step

摘要

We describe the fabrication and characterization of solid 3-dimensionalelectrodes in direct contact with microfluidic channels, implemented using asingle photolithography step, allowing operation in high-dielectric constantmedia. Incorporation and self-alignment of electrodes is achieved by combiningmicrosolidic approaches with exploitation of the surface tension of low meltingpoint alloys. Thus the metal forms the walls flanking the channel. We show thatthis approach yields electrodes with a well-defined, reproducible morphologyand stable electronic properties when in contact with biochemical buffers. Bycombining calibration of the electric field with free-flow electrophoresis wequantify the net solvated charges of small molecules.