We have fabricated a low-cost and flexible NH3 gas sensor using thermal ink-jet printing. The poly (3,4-ethylene dioxythiophene) doped with polystyrene sulfonated acid (PEDOT/PSS) with thickness of ~ 2 μm was used as a sensing film. The interdigitated electrode using patterned aluminum plate was attached over the sensing film. Atomic force microscopy results show the high homogeneous film and only small roughness is presented on the sensing film. This sensor exhibits high selectivity and sensitivity to NH3 at room temperature. The sensor response works linearly with gas concentrations between 100-1000 ppm. The modulation of conducting polymer/metal electrode interface plays a role in the sensing mechanism of NH3. Changes in the position of interdigitated electrodes can change the dominant sensing mechanism of typical polymer gas sensor.
Effect of Ni-Cr-Fe powder formulation on performance of porous materials based on Ink-jet Printing technology