Fabrication of miniature Clark oxygen sensor integrated with microstructure

A miniature Clark-type oxygen sensor has been integrated with a microstructure using a novel fabrication technique. The oxygen chip consists of a glass substrate with a three-electrode configuration, which is separated and connected by a groove, and a poly(dimethylsiloxane) (PDMS) container with an immobilized PDMS oxygen-permeable membrane. The assembly of the different substrates only uses the O2 plasma bonding technique, and the fabrication temperatures do not exceed 95 °C. Characteristics of the miniature sensor include the fastest response time of 6.8 s, good linearity with a correlation coefficient of 0.995, and a long lifetime of at least 60 h. The present miniature Clark oxygen sensor can be readily integrated with a microfluidic system to form a μ-TAS.