A Single-Walled Carbon Nanotube Network Gas Sensing Device

The goal of this research was to develop a chemical gas sensing device based on single-walled carbon nanotube (SWCNT) networks. The SWCNT networks are synthesized on Al2O3-deposted SiO2/Si substrates with 10 nm-thick Fe as the catalyst precursor layer using microwave plasma chemical vapor deposition (MPCVD). The development of interconnected SWCNT networks can be exploited to recognize the identities of different chemical gases by the strength of their particular surface adsorptive and desorptive responses to various types of chemical vapors. The physical responses on the surface of the SWCNT networks cause superficial changes in the electric charge that can be converted into electronic signals for identification. In this study, we tested NO2 and NH3 vapors at ppm levels at room temperature with our self-made gas sensing device, which was able to obtain responses to sensitivity changes with a concentration of 10 ppm for NO2 and 24 ppm for NH3

An investigation into spike-based neuromorphic approaches for artificial olfactory systems

The implementation of neuromorphic methods has delivered promising results for vision and auditory sensors. These methods focus on mimicking the neuro-biological architecture to generate and process spike-based information with minimal power consumption. With increasing interest in developing low-power and robust chemical sensors, the application of neuromorphic engineering concepts for electronic noses has provided an impetus for research focusing on improving these instruments. While conventional e-noses apply computationally expensive and power-consuming data-processing strategies, neuromorphic olfactory sensors implement the biological olfaction principles found in humans and insects to simplify the handling of multivariate sensory data by generating and processing spike-based information. Over the last decade, research on neuromorphic olfaction has established the capability of these sensors to tackle problems that plague the current e-nose implementations such as drift, response time, portability, power consumption and size. This article brings together the key contributions in neuromorphic olfaction and identifies future research directions to develop near-real-time olfactory sensors that can be implemented for a range of applications such as biosecurity and environmental monitoring. Furthermore, we aim to expose the computational parallels between neuromorphic olfaction and gustation for future research focusing on the correlation of these senses

Development of Amino Functionalized Graphene Based Polymer Nanofibers for Gas Sensors

RÉSUMÉ: Ces dernières années, la préparation d'architectures nanostructurées a été une stratégie importante pour améliorer les performances de détection de gaz. Ces matériaux ont un rapport surface / volume extrêmement élevé et ont des structures avec une nanoporosité élevée, ce qui augmente l’adsorption des gaz. Parmi ces nanomatériaux, le graphène fonctionnalisé a suscité un intérêt considérable pour l’application en détection du fait de sa conductivité variable, ce qui le rend disponible pour les phénomènes de transport d'électrons à très grande mobilité électrique en présence de gaz oxydants et réducteurs. De plus, la polyaniline (PANI) est facilement synthétisée et la structure de sa chaîne moléculaire peut être modifiée de manière pratique par copolymérisation ou dérivations structurelles. Grace à ses propriétés électriques, électrochimiques et optiques uniques, elle peut également être utilisée comme détecteur efficace pour la surveillance de composés organiques et inorganiques.----------ABSTRACT: In recent years, the preparation of nanostructured architectures has been an important strategy for improving gas sensing performance. These materials have an extremely high surface-to-volume ratio and high nanoporous structures, which increases the adsorption of gases. Among these nanomaterials, functionalized graphene has generated considerable interest in sensing applications owing to its variable conductivity, which makes it available for electron transport phenomena with very high electrical mobility in the presence of oxidizing and reducing gases. Additionally, polyaniline (PANI) is easily synthesized and its molecular chain structure can be modified conveniently by copolymerization or structural derivations. Due to its unique electrical, electrochemical, and optical properties, it can also be utilized as efficient sensors for monitoring organic and inorganic compounds