Detection of Odorant using TFT multi-array with Various Polymers

High selectivity of the sensor is one of the most important parameters for the electronic nose (E-nose) or gas sensor. However, many sensors have shown poor selectivity, even though some had high sensitivity. To solve this issue, we suggested a multi-sensor array concept, which consisted of thin-film transistors (TFTs) with various polymer selectors. By using TFT as a base sensor structure, sensitivity was significantly enhanced, and by adopting a polymer as the second dielectric layer, there was a remarkable improvement in selectivity. Some polymers showed unique selectivity to a specific odorant, whereas others had a moderate reaction to various odorants. Instead of common one-to-one matching between a sensor and an odorant, we used multi-output analysis using a dimensional bar chart. Eight different polymers TFTs made a specific chart pattern for four different odorants. Therefore, this sensor array and signal process concept can apply to the e-nose system, which can classify many odorants like a human simulator.