Ordered Ultrathin Films based on Conducting Polymers for Gas Sensors

Gas sensors based on metal oxides are known to be widely used for the detection of gases, aromatic hydrocarbon, etc., but such sensors lack selectivity, and operation at high temperatures is required. We have proved feasibility of our approach in Phase I, which focused on the use of highly organized ultrathin films of conducting polymers synthesized/processed via the layer-by-layer self-assembly technique for the first time relative to gas sensing application with emphasis on sensitivity and selectivity that are otherwise unattainable with other fabrication methods or materials. We have obtained excellent results relative to several aspects of the technology, particularly sensitivity and selectivity using few molecular layers of the different polymers. In the proposed Phase II program, we plan to optimize selected materials and their processing based on the feasibility study, and to elaborate on the viability of their sensors with respect to stability towards humidity, and heat, and gravity effects. We will also conduct thorough experiments to establish high selectivity while maintaining ppb detection level capability. Full characterization of single or multi-sensors will be performed towards maturing the technology and fabrication of prototypes that will be used for evaluation by NASA and for commercialization purposes in collaboration with HRL Laboratories.