Rational Design of Semiconductor‐Based Chemiresistors and their Libraries for Next‐Generation Artificial Olfaction

Artificial olfaction based on gas sensor arrays aims to substitute for, support, and surpass human olfaction. Like mammalian olfaction, a larger number of sensors and more signal processing are crucial for strengthening artificial olfaction. Due to rapid progress in computing capabilities and machine‐learning algorithms, on‐demand high‐performance artificial olfaction that can eclipse human olfaction becomes inevitable once diverse and versatile gas sensing materials are provided. Here, rational strategies to design a myriad of different semiconductor‐based chemiresistors and to grow gas sensing libraries enough to identify a wide range of odors and gases are reviewed, discussed, and suggested. Key approaches include the use of p‐type oxide semiconductors, multinary perovskite and spinel oxides, carbon‐based materials, metal chalcogenides, their heterostructures, as well as heterocomposites as distinctive sensing materials, the utilization of bilayer sensor design, the design of robust sensing materials, and the high‐throughput screening of sensing materials. In addition, the state‐of‐the‐art and key issues in the implementation of electronic noses are discussed. Finally, a perspective on chemiresistive sensing materials for next‐generation artificial olfaction is provided. A variety of material design strategies for the realization of next‐generation artificial olfaction are investigated. Inspired by the mammalian olfactory system, state‐of‐the‐art electronic noses will have diverse material libraries coupled with advanced signal processors that can replace and/or surpass the human olfactory system. These electronic noses are expected to be applicable to numerous on‐demand application fields.