Development of microsensors for chloride concentration in concrete

Chloride infiltration into concrete structures causes corrosion of steel reinforcing rods and eventual failure. Here we report on a three-electrode electrochemical sensor suitable for monitoring chloride concentrations in concrete. We use voltammetry to characterize the sensor for stability and sensitivity in KCl and NaClO solutions. We also outline a process for fabrication of an integrated microsensor and demonstrate crucial process steps for the formation of electrodes on a CMOS chip.