TAGRA 2025

Ethanol is a colourless, volatile, and flammable liquid that is widely used in industrial, medical, and consumer applications. However, prolonged ethanol exposure to humans at 1000 ppm and above can pose a serious health risk with symptoms such as throat irritation, dizziness, intoxication, and unconsciousness if the concentration continues to increase. This makes the detection of ethanol essential in applications such as industrial safety, breath analysis, and environmental monitoring. Thus, this study proposes a gas sensor to detect ethanol using three different metal-oxide semiconductors, which are Titanium Dioxide (TiO2), Nickel Oxide (NiO), and Zinc Oxide (ZnO) at room temperature. The sensors were fabricated using a screen-printing method by implementing an interdigitated electrode as the first layer and metal-oxide semiconductor paste as the second layer on a Kapton film. Silver paste was used as an interdigitated electrode and fired at 150ºC for 15 minutes in an oven. The metal-oxide semiconductor paste was prepared by mixing the sensing powder (TiO2, NiO, and ZnO) with a binder. All sensing layers were annealed at 200ºC for one hour in an oven. The results indicated that all sensors responded to 35,000 ppm of ethanol at room temperature. The sensing response was approximately 85.61%, 19.12%, and 11.64% for ZnO, NiO, and TiO2, respectively. The result revealed that ZnO is the best sensor for ethanol with the highest sensing response as compared to NiO and TiO2. This research can be applied in developing low-powered gas sensors that are effective in detecting ethanol presence to ensure workplace safety and monitoring procedures.