A Compact 16-Channel Input Thermally Adsorption-/Desorption-Controlled Intelligent Odor Sensing System

In this study, we developed a compact thermally adsorption-/desorption-controlled odor sensing system (TC-OSS). The absorption and desorption of odor molecules or volatile organic compounds (VOCs) are controlled by sensor temperature giving a high resistance value in a VOC adsorbed state at low temperature and a low resistance in a VOC desorbed state at a high temperature. The system eliminates many gas flow control parts required in conventional odor sensing systems realizing a significant compactness. The developed TC-OSS comprises a 16-channel VOC sensing elements array fabricated on a small heater showing high sensitivity (3-ppb sensing capability with signal-to-noise ratio (SNR) as high as ~15 dB). With the assistance of artificial intelligence (AI) postprocessing, a discriminative classifier of five standard VOCs with high a successful probability (~95.8%) is demonstrated.