Patterning electrodes using procedure

In another work, Parra and coworkers proposed a method based on chemically modified voltammetric electrodes for the identification of adulterations made in wine samples, by addition of a number of forbidden adulterants frequently used in the wine industry to improve the organoleptic characteristics of wines, like, for example, tartaric acid, tannic acid, sucrose, and acetaldehyde (Parra et ah, 2006b). The patterns identified via PCA allowed an efficient detection of the wine samples that had been artificially modified. In the same study, PLS regression was applied for a quantitative prediction of the substances added. Model performances were evaluated by means of a cross-validation procedure. 

An alternative strategy is to deposit a positive photoresist to mask areas where electrode material is to be absent. Upon exposure through the mask and development, the base substrate will be exposed where the electrode components are to be deposited. The electrode materials are then typically deposited over both the bare substrate and the photoresist. A liftoff procedure is then used to remove both the photoresist and excess deposited electrode film material by swelling the photoresist polymer in a suitable solvent, leaving the electrode array behind [40,45,47] with the underlying substrate also exposed in regions where no electrode is present. Increasingly complex patterns of application of multiple... 

Rote et al. (1993, 1994) used a carotid thrombosis model in dogs. A calibrated electromagnetic flow meter was placed on each common carotid artery proximal to both the point of insertion of an intravascular electrode and a mechanical constrictor. The external constrictor was adjusted with a screw until the pulsatile flow pattern decreased by 25 % without altering the mean blood flow. Electrolytic injury to the intimal surface was accomplished with the use of an intravascular electrode composed of a Teflon-insulated silver-coated copper wire connected to the positive pole of a 9-V nickel-cadmium battery in series with a 250000 ohm variable resistor. The cathode was connected to a subcutaneous site. Injury was initiated in the right carotid artery by application of a 150 xA continuous pulse anodal direct current to the intimal surface of the vessel for a maximum duration of 3 h or for 30 min beyond the time of complete vessel occlusion as determined by the blood flow recording. Upon completion of the study on the right carotid, the procedure for induction of vessel wall injury was repeated on the left carotid artery after administration of the test drug. 

Figure 5.5.18 illustrates the ScL procedure used by Loo and coworkers to fabricate laminated pentacene TFTs. The top substrate, containing the [tCP-printed source and drain electrodes, was constructed on a PDMS-coated plastic substrate [89]. The bottom substrate was constructed on an ITO-coated plastic substrate. The ITO, patterned photo lithographically to define the gate level, was coated with an organosilesquioxane spin-on glass, which comprises the dielectric. Pentacene [44]... 

Preliminary results are presented for the use of cyclic voltammetiy as a method for pattern recognition. The current at eight potentials of a cyclic voltammgramm was analyzed and these values served as a simulation of eight amperometric sensors. It is shown that on the basis of this procedure, different explosives and apple juices are easily distinguished by the use of one electrode alone These results clearly show that cyclic voltammetry could easily be used for a so called electronic tongue. In the future it is planned to use cyclic voltammetry as a method in combination with different sensor methods and also for the vapour detection. 

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