Sensing membranes Sol-gels Thermoelectric equipment Thin films Titanium dioxide Titanium oxides pH sensors Annealing Annealing process Annealing time Bilayer composites Composite films Drying Drying temperature Electronic equipment Extended gate field effect transistor (EGFET) Extended gate field effect transistors Field effect transistors II-VI semiconductors Indium Indium tin oxide substrates Oxides PH response PH sensitivity Sensing performance Sensitivity values Sol-gel spin coating method Temperature distribution Thin film circuits Tin dioxide