Multicomponent polymer electrolytes: new extremely versatile receptor materials for gas sensors (VOC monitoring) and electronic noses (odour identification/discrimination)

A new class of receptor materials for gas sensors for volatile organic compounds (VOC) was developed: multicomponent polymer electrolytes (MPE). An MPE usually consists of three components: a polymer, a plasticiser, and an organic salt. In an extensive systematic study more than 500 compositions using 7 polymers, 8 plasticisers, and 4 organic salts were tested in order to investigate the effect of individual components and their ratio on the gas sensing properties (selectivity, sensitivity, etc.) of MPE. The operation of a MPE-based gas sensor is based on a variation of the bulk ionic conductivity of the receptor layer due to adsorption of an ambient vapour. The specific conductance of the used materials is usually between 0.1 /spl mu/S/cm and 10 /spl mu/S/cm and it may change more than 100 times in the dynamic range of the gas sensor, which stretches typically from low ppm up to some 10000 ppm. The MPE-based gas sensor based on miniaturised interdigitated transducers demonstrate a remarkable variety of their properties depending on the MPE composition. The performance of single sensors and composed of them sensor arrays was thoroughly studied.