MEMS needle-type sensor array for in situ measurements of dissolved oxygen and redox potential.
Microelectrodes are among the most accurate and reliable monitoring devices for measuring the dynamics of biofilm processes. This paper describes a novel needle-type microelectrode array (MEA) for simultaneous in situ measurements of dissolved oxygen (DO) and oxidation reduction potential (ORP) fabricated using microelectromechanical systems (MEMS) technologies. The MEA exhibits fast response times for both DO and ORP measurements and shows a substantial increase in DO sensitivity. To demonstrate the versatility of the new sensor, it was applied to the measurement of DO and ORP microprofiles in a multispecies biofilm. This work demonstrates that the MEA is able to monitor local concentration changes with a high spatial resolution and provide the versatility of the microelectrode technique needed for biofilm studies as well as the capability for repetitive measurements. In addition, the use of MEMS technologies and batch fabrication approaches enables integration, high consistency, high yields, and mass production. With further development, it may be possible to add additional sensors to the MEA (e.g., pH, phosphate) and integrate them with a reference electrode.
Lee
Jin-Hwan
JH
Department of Electrical and Computer Engineering, University of Cincinnati, Cincinnati, Ohio 45221, USA.
Seo
Youngwoo
Y
Lim
Tae-Sun
TS
Bishop
Paul L
PL
Papautsky
Ian
I
D018441:Biofilms; D015374:Biosensing Techniques; D002138:Calibration; D004563:Electrochemistry / Q000379:methods*; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D008839:Microelectrodes; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D012107:Research Design; D014865:Waste Disposal, Fluid; D014873:Water Pollutants / Q000737:chemistry; D018508:Water Purification
D010710:Phosphates; D014873:Water Pollutants; D010100:Oxygen