Research that leads to a clear path for the development of fast, rugged, extremely sensitive sensors for real-time detection of chemical warfare agents is central to the implementation of any chemical weapons treaty, the safety of troops in the battlefield and personnel close to storage facilities. The objective of this proposal is to develop a novel microsensor technology for detection of chemical warfare agents based upon an Oak Ridge National Laboratory patent pending photothermal detection technique. It is expected to provide real-time, continuous monitoring of target chemicals in the sub-ppb level. These sensors are based on the determination of the photothermal signature of chemicals absorbed on the surface of a thermal detector. Vapors from the target chemical are drawn into contact with surface of a sensitive thermal detector; the active detector surface would be coated with an appropriate chemical layer which has an affinity for the family of the target chemical. For example, self assembled composite monolayer coatings are suitable for organophoshonate compounds which serve as model chemical warfare agent simulants. Thermal changes resulting from the adsorption of molecules can be detected as changes in electrical resistance (when a micro-bolometer is used as a thermal detector). Next, a photothermal spectrum is obtained for the chemicals absorbed on the thermal detector surface by scanning a broadband wavelength region with the aid of a monochromator/micro-spectrometer across a linear array of such detector pixels. The photothermal spectrum provides a unique signature for the target chemical absorbed on the detector surface
