Discrimination of structurally similar odorous molecules with various concentrations by using a nanomechanical sensor

A pattern recognition-based chemical sensor array is an efficient approach to discriminating odours, while the fluctuation in the concentration of odorous molecules often results in concentration- dependent patterns rather than the ones based on chemical proper- ties. Here, we present the discrimination of odorous molecules based on the chemical properties with reduced influence of their concen- trations in a wide range from ppm to ppb levels using a nano- mechanical sensor. Extraction of effective features, which are less affected by concentrations of odorous molecules, from sensing signals leads to successful discrimination of each chemical species even in a series with similar physical structures.