| Summary: | 博士 === 大同大學 === 材料工程學系(所) === 94 === In this study, the design of the sensitive device is employed to improve the sensitive effects by varying the construction, pattern, size, width, and inter-distance of the electrode. The purpose is to increase the effective width and reduce the inter-distance of the electrodes. For fabricating the humidity sensitive layer, the monomeric solution of organic electrolyte NaSS was spin-coated on the designed electrodes with different patterns and then exposed to UV-light to induce grafting polymerization. From the results, the circular sensitive electrode with higher W/I value has the lower impedance and shows about 3 orders of change in the impedance for the variation of relative humidity from 40 to 90%. The plasma deposition and surface grafting polymerization have been used to modify the surface structure and properties of inorganic substrates such as organic nature, structural constitution, hydrophilicity, functional groups, and conductivity. In this study, tin oxide (SnOx) organic-like thin films were deposited by plasma enhanced chemical vapor deposition (PECVD) of tetramethyltin (TMT) and O2 gas mixtures at low temperature. The organic-like thin films containing peroxides or free radicals can be subsequently grafted hydrophilic polymer acrylamide (AAm) by UV-induced grafting polymerization. Plasma-deposited thin films were prepared from PECVD of acetylene (C2H2), acetylene/nitrogen (C2H2/N2), or acetylene/ammonia (C2H2/NH3). When N2 or NH3 was mixed with C2H2 in the feed, the films were identified to contain all elements of the mixture and the properties of the films were implied by the C–H bonds and nitrogen functionalities. The resistance of the thin films measured at ambient environment is over 108 Ω near electric insulator and independent of humidity. It is found that the resistance of the thin film sensors prepared from C2H2, C2H2/N2, and C2H2/NH3 is distinctly decreased by over 2 orders of magnitude by the adsorption of ethanol vapor.
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