A synthetic diamond conductivity sensor: Design rules and applications
By Joseph, Maxim B.; Colburn, Alex; Mollart, Timothy P.; Palmer, Nicola; Newton, Mark E.; Macpherson, Julie V.
Published in Sensors and Actuators B: Chemical
2017
Abstract
Abstract Solution conductivity sensors (electrodes) are widely used in industrial and research settings to make measurements across the wide range of conductivities found in aqueous solutions, from distilled water to concentrated salts and acids. However, changes in electrode geometry as a result of mechanical wear, surface fouling or chemical attack result in changes to sensor performance, necessitating regular recalibration. Furthermore, direct contact with solution means exposed electrodes are susceptible to surface fouling or corrosion. In this paper we describe, a corrosion resistant, mechanically robust conductivity sensor fabricated from synthetically grown insulating and conducting diamond, using scalable chemical vapor deposition. In particular, using a two-step growth procedure pairs of co-planar conducting diamond band electrodes are integrated into an insulating diamond platform in a two point probe arrangement on a 10 mm