THE APPLICATION OF EXCIMER-LASER MICROMACHINING FOR THE FABRICATION OF DISC MICROELECTRODES

A method is presented for the fabrication of carbon ink microelectrode s in a composite membrane or thin laminate arrangement. The scheme uti lises uv excimer laser photoablation of nanosecond pulse duration at w avelength 248 nm to generate the required micro-hole structure in 12 m um PET film. At laser fluences of the order of 1.0 mJ cm-2, film ablat ion rates were controlled to 0.4 mum per pulse without thermal deforma tion of the micro-hole. From a micro-hole template a thick film printi ng technique is used to produce carbon ink microelectrodes with an inl aid disc geometry. A series of microelectrode devices were constructed by this process with disc diameters ranging from 38 mum down to 7 mum with fabrication precision to 1 mum. The amperometric response of the film based microelectrodes were characterized using standard electroc hemical measurements and examined by SEM and optical microscopy. Appli cations are proposed for the new device in the assembly of electrochem ical transducers for environmental or clinical sensors.