Array, sensor

The sensor cells are addressed using the active matrix addressing technique, using two decoders one that acts as a colnmn driver and the other that acts as a row selector. These two decoders are synchronised using two binary counters one that iterates 

---

Linear paraffins Linear programming Linear rollback model Linear sensor arrays Linear superelasticity Linear topology Linear units Linen... 

Since 1970 the subject of amoiphous semiconductors, in particular silicon, has progressed from obscurity to product commercialisation such as flat-panel hquid crystal displays, linear sensor arrays for facsimile machines, inexpensive solar panels, electrophotography, etc. Many other appHcations are at the developmental stage such as nuclear particle detectors, medical imaging, spatial light modulators for optical computing, and switches in neural networks (1,2). 

FIGURE 6-21 A silicon-based sensor array for monitoring various blood electrolytes, gases, and metabolites. (Courtesy of i-STAT Co.)... 

FIGURE 6-24 Response pattern of an amperometric sensor array for various carbohydrates. The array comprised carbon-paste electrodes doped with CoO (1), Cu20 (2), NiO (3) and Ru02 (4). (Reproduced with permission from reference 84.)... 

Explain clearly why highly selective individual electrodes are not deshed for the operation of sensor arrays. 

C.W. McCarrick, D.T. Ohmer, L.A. Gilliland, P.A. Edwards and H.T. Mayfield, Fuel identification by neural network analysis of the responses of vapour-sensitive sensor arrays. Anal. Chem., 68 (1996) 4264-4269. 

Active matrix addressing can also be used in printer heads [628] and linear sensor arrays [629]. a-Si H TFTs are used to address a linear array of output or input transducers, respectively. In the linear sensor array, u-Si H photodiodes are used. 

Multiple electrodes have been used to obtain selectivity in electrochemical detection. An early example involved the separation of catecholamines from human plasma using a Vydac (The Separation Group Hesperia, CA) SCX cation exchange column eluted with phosphate-EDTA.61 A sensor array using metal oxide-modified surfaces was used with flow injection to analyze multicomponent mixtures of amino acids and sugars.62 An example of the selectivity provided by a multi-electrode system is shown in Figure 2.63... 

Chen, Q., Wang, J., Rayson, G., Tian, B., and Lin, Y., Sensor array for carbohydrates and amino acids based on electrocatalytic modified electrodes, Anal. Chem., 65, 251, 1993. 

The electronic nose is an example of an area in which the complexity of the analysis may make it difficult to replace a human with an ES. Electronic noses combine a sensor array with a neural network to make judgments about the composition of complex mixtures, such as fuels, wines, and natural oils. In such tasks, they often beat human noses in accuracy (Figure 7.8). 

Demchenko AP (2005) The future of fluorescence sensor arrays. Trends Biotechnol 23 456 160... 

K.S. Bronk, D.R. Walt 1994 pH sensor array using fiber bundles... 

Mayr T., Igel C., Liehsch G., Klimant I., Wolfbeis O.S., Cross-Reactive Metal Ion Sensor Array in a Micro Titer Plate Format, Anal. Chem. 2003 75 4389-4396. 

Note that in future application of photonic bandgap structures may result in very small sensor (-array)s. 

The combination of pin printing and sol-gel processing techniques provides a simple method to rapidly fabricate reusable chemical sensor element into arrays that exhibit good analytical figures of merit. This methodology also provides a straightforward means to fabricate reusable sensor arrays for simultaneous multianalyte quantification. 

Cho E., Bridht F., Pin-printed chemical sensor arrays for simultaneous multianalyte quantification, Anal. Chem. 2002 74 1462-1466. 

Another approach to analyze the multi-sensor array responses is the ensemble approach11, which does not require decoding and therefore, speeds up the identification process. The analysis in this approach uses combined response profiles of the entire undecoded array as a single response (Figure 6). 

In addition, a linear dependence was found between the concentration of DNB and its fluorescence response profile. All these characteristics demonstrate that this sensor array is suitable for use in detecting explosive vapors. 

Michael K. L., Taylor L. C., Schultz S. L., Walt D. R., Randomly ordered addressable high-density optical sensor arrays, Anal. Chem. 1998 70 1242-48. 

---