Gas sensing based on organic composite materials: Review of sensor types, progresses and challenges

Over the past decade, organic semiconductors and renewable resources have aroused great interest in basic research and practical applications. Composites based on organic materials and materials of biological origin, if not all bio-based, are potentially abundant and partly biodegradable. These materials have demonstrated advantages making them ideally suited for gas-sensing applications. Herein, we present different detection principles of gas sensing, such as electrochemical, resistive, capacitive, and acoustic sensors. Besides, we describe sensing properties and suitable materials to enhance the selectivity, sensitivity and response/recovery time of gas sensors. In addition, an overview of different forms of materials based on renewable resources and inorganic/organic semiconductors, as well as the development of different types of sensors are discussed. Finally, challenges and future directions are examined in order to develop a low-cost microscale sensing technology using composite materials based on renewable resources. We anticipate that chemical engineering, computer science, machine learning and embedded systems can contribute to the development of new sensing materials.