Design of a very large chemical sensor system for mimicking biological olfaction

Olfactory receptor neurons in the mammalian olfactory system transduce the odour information into electrical signals and project these into the olfactory bulb. In the biological system the huge redundancy and the massive convergence of the olfactory receptor neurons to the olfactory bulb are thought to enhance the sensitivity and selectivity of the system. To explore this concept a polymeric chemical sensor array consisting of 216 (65,536) sensors comprising tens of different types will be built in the frame of the FP7 NEUROCHEM project. To interface such a large sensor array, a topological array configuration with n rows and m columns has been adopted in order to reduce the total wiring connections to n + m. A detailed numerical analysis of the electrical crosstalk deriving from such a configuration has been carried out for elucidating advantages and limitations of the scanning algorithm. A prototype of the transducing array has been designed and an electronic scanning system capable of reading the 65,536 sensing elements array has been realized.