Uncertainty Sources in Aerosol Jet Printed and Flexible Electrochemical Sensors

Electrochemical sensors are nowadays used in a wide set of applications even though they still present major issues that weaken their metrological characteristics. Among those, noise is interesting because determines the lowest detectable concentration and allows developing better models for electrochemical sensors. In this work, a set of flexible electrochemical sensors produced by Aerosol Jet Printing (AJP) are analyzed to identify their different noise and uncertainty sources. Different conditions such as analyte concentration variations and temperature fluctuations are taken into consideration. Effects on noise of processes inherently connected with the transduction principle such as double-layer capacitance and mass transport were observed as well as a correlation between the analyte concentration and the overall noise. Thermal effects analysis revealed an overall increment of the noise level up to 52.4% in a 10 degrees C interval while a variation of over 100% of the mean output current on the same interval are recorded. According to the results presented in this work, noise and temperature effects should be taken into consideration in the design of novel electrochemical devices to improve their reliability in uncontrolled conditions.