What’s that Smell?: Thermally Modulated Machine Olfaction by Joule Heating to Detect And Identify Odourant Molecules

Abstract

The olfactory sense is one of the first evolved by early life. Mimicking olfaction through artificial systems provides a crucial understanding of the world and surroundings. The field of machine olfaction aims to achieve just this goal. In this work, the use of a thermally modulated, chemically diverse carbon black-polymer composite sensor array is shown to be able to identify and quantify a variety of odourant analytes. As mammalian olfaction relies on sniffing to maintain a constant response within the brain, so too does thermal modulation provide a drift-resistant peak-to-peak response. Through the sorption and desorption of analyte, the connectivity within the composite will change, causing percolation network-driven changes in resistance, allowing for quantification. The degree of resistive change between exposures of various analytes is unique, providing a fingerprint-like response from an array of sensors. This work demonstrates that both analyte concentration and identity are captured by modulated signal amplitude.