Contactless Conductivity Detector in PDMS Microfluidic System

We present a new contactless conductivity detector for microfluidic system. In traditional conductivity detectors, the electrodes are in direct contact with analyte. In the presented microsystem, the electrodes are made of microchannels filled with solution of KCl – the technological solution called as pseudoelectrodes. Microfluidic system was fabricated in poly(dimethylsiloxane) PDMS, during a photolithography process. During the tests, dimension, type of the filling electrolyte and lay-out of pseudoelectrodes ’ microchannels were evaluated. Analyte was pumped into microchannels using a syringe pump. Repeatable changes in the signal were observed. Key words: contactless conductivity detector, pseudoelectrodes, PDM