Experimental setup to study poisoning effects of different materials on chemical sensors used in E-nose systems

Electronic nose (E-nose) technology relies on partially specific electronic chemical sensor arrays with an appropriate pattern recognition system housed in dedicated chambers and coupled with sampling systems to analyze simple or complex odors. An optimized design and dimensioning of the sensor chamber and sampling system can significantly improve sensor responses. In this context, the design of E-nose sampling systems has recently benefited from emerging technologies such as additive manufacturing (i.e., 3D printing) and innovative materials. While new materials can enable new functionalities in sensor housing construction, their potential gaseous emission can compromise sensor performance over time. More broadly, materials used in E-nose components and in the sampling environment can release volatile organic compounds (VOCs) that can irreversibly adsorb onto sensor surfaces, interfering with sensor functionality, also known as “poisoning”. This study aims to develop an initial experimental methodology and a dedicated setup to assess the potential poisoning effect of materials commonly used in E-nose components or typically found in the sampling environment – PEEK (polyetheretherketone), biocompatible resin and silicone – on gas sensor performance. For this purpose, two widely used commercial metal oxide semiconductor (SMOX) sensors (TGS2610 and TGS2611) were exposed to these materials in an accelerated poisoning test over 2 weeks. The results indicated that silicone and biocompatible 3D-printed resin, even after thermal pre-treatment, significantly altered sensor responses, whereas PEEK did not show any effect on sensor sensitivity over the test duration.