Design and Fabrication of All Organic Field Effect Transistor

All organic field effect transistor consist of poly-3-hexyloxythiophene, undoped poly-3,3”-didecyl-2,2’,5’,2”-terthiophene and polypyrrole has been successfully developed. Poly-3-hexyloxythiophene was applied as gate material. Undoped poly-3,3”-didecyl-2,2’,5’,2”-terthiophene was used as insulating layer and polypyrrole was applied as source-drain material. The multilayer polymers were deposited onto gold source-drain and gate electrodes by electropolymerization method. The spaces between the gold electrodes were 50 μm. The transistor shows a current amplification upon increasing gate voltages. Good conductivity stability upon increasing gate voltages was observed. Overall the field effect transistor has properties that similar to inorganic field effect transistor

Artificial Olfaction in the 21st Century

The human olfactory system remains one of the most challenging biological systems to replicate. Humans use it without thinking, where it can measure offer protection from harm and bring enjoyment in equal measure. It is the system's real-time ability to detect and analyze complex odors that makes it difficult to replicate. The field of artificial olfaction has recruited and stimulated interdisciplinary research and commercial development for several applications that include malodor measurement, medical diagnostics, food and beverage quality, environment and security. Over the last century, innovative engineers and scientists have been focused on solving a range of problems associated with measurement and control of odor. The IEEE Sensors Journal has published Special Issues on olfaction in 2002 and 2012. Here we continue that coverage. In this article, we summarize early work in the 20th Century that served as the foundation upon which we have been building our odor-monitoring instrumental and measurement systems. We then examine the current state of the art that has been achieved over the last two decades as we have transitioned into the 21st Century. Much has been accomplished, but great progress is needed in sensor technology, system design, product manufacture and performance standards. In the final section, we predict levels of performance and ubiquitous applications that will be realized during in the mid to late 21st Century

Description and Characterisation of a Large Array of Sensors Mimicking an Artifical Olfactory Epithelium

Biological olfactory systems show high sensitivity and exquisite discriminatory capacity to odorants. These characteristics are due to hierarchical signal processing of the large numbers of sensory inputs that occurs within the olfactory system. In testing realistic computational models of the olfactory system, large numbers of chemical sensor inputs are required. So far, sensory devices that may serve as model inputs to an artificial olfactory system do not exist. The development of a large scale array of chemical sensors able to mimic the olfactory receptor neurons is described, and these have been characterised in terms of their variability and degree of redundancy. Using this device it is possible to start testing computational hypotheses appropriate to biological chemosensory systems and adapt them to the artificial olfaction