The large carbon dioxides produced by highly developed industries not only result in serious air pollution and health problems, but also cause ocean acidification and decrease the survival rate of fry in aquaculture. Therefore, to develop a system for real-time detection of the concentration of carbon dioxide in aquaculture has become a very important research issue. Optical analysis and gas-chromatography are the two main methods adopted in conventional gas detection. Although the conventional carbon dioxide detectors presented high sensitivity and accuracy, the high fabrication cost, large dimension, low capability of batch fabrication and without real-time monitoring function will limit their applications. This thesis utilizes MEMS technology to implement an extended-gate field-effect transistor (EGFET) with an integrated gas permeable membrane for development of a high-sensitivity, small size and low cost carbon dioxide microsensor. The main material of the carbon dioxide gas permeable membrane adopted in this research is dioctyl sebacate. The main processing steps of the proposed microsensor include four photolithography and four thin-film deposition processes. In addition, the influences of the channel width/length ratio of EGFET and the coating of gas permeable membrane on the sensing performances of presented microsensor are also investigated in this study. The chip size of the implemented carbon dioxide microsensor is 11 mm¡Ñ13 mm¡Ñ 0.5 mm and the sensing area is 1 mm¡Ñ1 mm. As the carbon dioxide concentration varies from 0.25 mM to 50 mM, a very high sensitivity (42.3 mV/ppm) and sensing linearity (99.2%) of the proposed EGFET microsensor can be demonstrated. In addition, the response time of the presented carbon dioxide microsensor is only about 100 seconds, hence it is very suitable for developing a real-time monitoring microsystem.

Several experiments were designed for utilization of fluorescence spectroscopy as a method of aerosol particle detection in a model of lungs. One of the experiments was to arranged use luminescent properties of DEHS (bis(2-ethylhexyl)decandioate) for calculating aerosol deposition. The outcome of this experiment was confirmation of clusters existence, which causes luminescence of DEHS. But the luminescence is not enough dependent on concentration and as such is not suitable for calculation of aerosol deposition. As the next experiment DEHS-fluorescein particles were generated by condensation monodisperse aerosol generator (CMAG), where water was used instead of isopropyl alcohol as a solvent. By this alteration the negative influence of DEHS was eliminated, which caused results refinements of aerosol deposition. Generation of fluorescein sodium salt particles by small-scale powder disperser (SSPD) was designed as a last experiment. The lower deposition efficiency measured by this method was caused by particles polydispersion. Photo records were used for documentation of Hot-spots. Outcomes of this study are new knowledge of fluorescence spectroscopy utilization for study of aerosol deposition and possibilities of fluorescent aerosol particles generation. Acquired data can serve for knowledge extension of possible detection methods for aerosol particles in the model of lung and can serve for validation of numerical simulations.