This paper describes a new contactless conductivity detector, whose electrodes are constructed of microchannels filled with solution of KCl -called pseudoelectrodes. The lab-on-a-chip microdevice was fabricated in poly(dimethylsiloxane) PDMS, using a moulding technique. The mould was made from a dry negative photoresist with a thickness of 50 μm. During the tests, the dimension and arrangement of pseudoelectrodes` microchannels were evaluated. The analyte was pumped into the microchannel using a syringe pump with a flow rate of 50 μL/min. Reproducible changes of the signal were obtained.

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.