Microfabricated solid-state dissolved oxygen sensor

This paper describes the design, fabrication and testing of a microfabricated oxygen concentration sensor consisting of a microfabricated thin-film electrode matrix overlaid with a solid-state proton conductive matrix (PCM) and encapsulated in a bio-inert polytetrafluoroethelene (PTFE) film. Through cyclic voltammetry (CV) and voltage step (VS) measurements, the device was shown to have a linear response with respect to dissolved oxygen concentration over a range from 0 to 601 muM (0-200 atm% O-2). The diffusion constant of the PCM was measured to be D-1 = 1.7 x 10(-10) m(2)/s (+/-2.7 x 10(-11) m(2)/s,n = 40), which translates to a response time constant of r = 0.7 s (+/-0.11 s,n = 40). These results were consistent with those predicted by basic electrochemistry. (C) 2002 Published by Elsevier Science B.V.