Microfabricated thin-film microelectrode

Table 1 Comparison of several microfabricated thin-film microelectrode technologies... 

Electrode arrays have been microfabricated using a variety of methods and materials, including silicon, metal, ceramic, and polymers. The microfabrication processes for thin-film microelectrodes are already well established for these substrates. 

Microfabrication and micromachining techniques have also been used in the manufacture of electrochemical sensors. This includes po and pco sensors. Zhou et al [9] describe an amperometric CO2 sensor using microfabricated microelectrodes. In this development, silicon-based microfabrication techniques are used, including photolithographic reduction, chemical etching, and thin-film metallization. In Zhou s study, the working electrodes are in the shape of a microdisk, 10 pm in diameter, and are connected in parallel. In recent years, silicon-based microfabrication techniques have been applied to the development of microelectrochemical sensors for blood gases, i.e. P02. Pcoj and pH measurements. 

Low-aspect-ratio (ratio of the height of the microelectrode divided by its lateral dimension is larger than 0.2) microelectrode arrays are fabricated using conventional silicon-based microfabrication technologies, such as hthographic techniques to yield arrays of thin films of metallic or carbon electrodes on a silicon substrate. These arrays often have limited stability and life times as a result of defects in the metal layer poor resistance to corrosion is... 

Photolithography is the most diffused technique for the fabrication of regular arrays of microelectrodes. Photolithography is a microfabrication technique which is based on the selective removal of parts of thin films (photoresist) exposed to UV light. This procedure allows one to obtain regular arrays of micro electrodes with high spatial resolution, nonetheless this technique requires special and expensive equipments besides, the photolithographic process requires access to a clean room. 

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