A simple on-chip self-diagnosis/self-calibration method of oxygen microsensor using electrochemically generated bubbles

An on-demand in situ self-diagnosis and self-calibration of biochemical sensors is indispensable for continuous and reliable monitoring. An on-chip electrochemical actuation method (water electrolysis) was employed to achieve this novel functionality. A simple fluidics chip including a polydimethylsiloxan (PDMS) channel layer and platinum actuation electrodes was designed and fabricated. The performance of this system was evaluated in combination with a commercial fiber optic oxygen sensor. The results obtained from the fluidics chip were compared to those obtained from a solution phase and a dry gas phase and the influence of water vapor and internal pressure was discussed. This method is expected to enable an on-demand in situ self-diagnosis and self-calibration of oxygen microsensor during real-time monitoring and to lead to an integrated system with on-chip, built-in intelligence.