The use of more and more complex systems in transportation, bio medical devices, defence, production, systems, etc., that are more and more automated, having to comply with many norms related to low energy consumption, miniaturization, insensivity to modifications of the surrounding conditions, security, etc. induce the need of new sensors that have to be reliable, low cost, easy to produce, if possible without clean rooms, avoiding too demanding calibration process and using no poisonous components or materials.