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

A method is presented for the fabrication of carbon ink microelectrodes in a composite membrane or thin laminate arrangement. The scheme utilises uv excimer laser photoablation of nanosecond pulse duration at wavelength 248 nm to generate the required micro-hole structure in 12 mum PET film. At laser fluences of the order of 1.0 mJ cm-2, film ablation rates were controlled to 0.4 mum per pulse without thermal deformation of the micro-hole. From a micro-hole template a thick film printing technique is used to produce carbon ink microelectrodes with an inlaid 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 electrochemical measurements and examined by SEM and optical microscopy. Applications are proposed for the new device in the assembly of electrochemical transducers for environmental or clinical sensors.