Design and production of rare-earth elements doped ZnO/CuO composite thin films for continuous sweat rate monitoring

In this thesis, we focused on the utility and efficacy of bare and rare-earth (RE) elements (Cerium (Ce), Dysprosium (Dy) and Ytrium (Y)) doped nanostructured composite ZnO/CuO thin films in the application of real-time monitoring of sweat as a biological fluid. Nanostructured ZnO/CuO thin film samples were synthesized by using a low-cost and simple Successive Ionic Layer Adsorption and Reaction (SILAR) technique. The surface topographical, structural, and conductivity characteristics of the samples were examined by different versions of characterization techniques. The structural and surface morphological analyses showed that the main physical characteristics of the ZnO/CuO thin film materials were altered after the substitution of RE elements. The comparative artificial sweat sensing properties of the bare, Ce-doped, Y-doped and Dy-doped ZnO/CuO composite films were also researched. An important improvement in sweat rate sensing properties was observed for all of the RE elements doped films for all concentration levels. Also, bare and RE elements doped samples demonstrated a linear response for the selected five different concentrations range at room temperature. Comprehensive discussions were presented in the thesis regarding surface topography, crystalline structure, atomic radius, electronegativity, and conductivity. From the obtained these consequences, we can deduce that RE elements doped ZnO/CuO composite films could be utilized in real-time sweat rate monitoring with basic amperometric evaluations that do not suppose complicated preparation and instrumentation methods.