Flexible polymer foils equipped with sensors and waveguides have to be protected with stable coatings to enhance their environmental and mechanical stability without affecting their functionality. Promising materials for this function are nanocomposites mixed of organic and inorganic materials. Different approaches for the production of nanocomposites consisting of PTFE and silicon oxide as well as tantalum oxide are compared and first results are presented in this study. Ion beam sputtering is used in combination with a composite target consisting of PTFE and 25\% glass fibers as well as with a zone target consisting of PTFE and silicon in presence of oxygen. The third approach is the combination of ion beam sputtered PTFE with nanoparticles produced by a gas aggregation source. In this context, the chemical composition of the produced films is analyzed by energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR)