Gas Sensor Array with Polymer-Carbon Glue Composite Structures for Neural Network Application

In this study, we focus on the gas sensor array with semiconductor and neural network applications.Two different sensing membranes, namely, diluted conductive water-soluble carbon glue and polymer-carbon glue stacked membranes, were used for experiments to compare the differences and correlations between multiple polymers and multiple gases.In the experiments, the reactions of 13 different polymers with five gases (air, ethanol, CO, NO 2 , and NH 3 ) were tested.A set of sixteen array sensors with a line width of 50 µm and a sensing diameter of 3 mm were used, and such sensors were coated with a 300-nm-thick aluminum-doped zinc oxide (AZO) layer on the wafer surface.The gas sensitivity obtained using various polymers dripped on the sensing area was tested, and the sensitivity of small low-energy heterogeneous gassensing elements is discussed.It is concluded that the various gases considered have good separation properties and excellent selectivity and reproducibility.Among the two different sensing membranes, the gas reaction ratio of (ΔR/R) max = 149% is the most prominent relative to the resistance of carbon glue in reference to the air baseline; as a result, the carbon membrane showed a higher gas sensitivity than the polymer-carbon membrane.