Artificial olfactory sensor technology that mimics the olfactory mechanism: a comprehensive review

Abstract

Artificial olfactory sensors that recognize patterns transmitted by olfactory receptors are emerging as a technology for monitoring volatile organic compounds. Advances in statistical processing methods and data processing technology have made it possible to classify patterns in sensor arrays. Moreover, biomimetic olfactory recognition sensors in the form of pattern recognition have been developed. Deep learning and artificial intelligence technologies have enabled the classification of pattern data from more sensor arrays, and improved artificial olfactory sensor technology is being developed with the introduction of artificial neural networks. An example of an artificial olfactory sensor is the electronic nose. It is an array of various types of sensors, such as metal oxides, electrochemical sensors, surface acoustic waves, quartz crystal microbalances, organic dyes, colorimetric sensors, conductive polymers, and mass spectrometers. It can be tailored depending on the operating environment and the performance requirements of the artificial olfactory sensor. This review compiles artificial olfactory sensor technology based on olfactory mechanisms. We introduce the mechanisms of artificial olfactory sensors and examples used in food quality and stability assessment, environmental monitoring, and diagnostics. Although current artificial olfactory sensor technology has several limitations and there is limited commercialization owing to reliability and standardization issues, there is considerable potential for developing this technology. Artificial olfactory sensors are expected to be widely used in advanced pattern recognition and learning technologies, along with advanced sensor technology in the future.

Background

Biomimetics is an interdisciplinary field in which engineering, chemistry, and biology principles are applied to the synthesis of materials, synthetic systems, or machines that have functions mimicking biological processes [1]. Humans have continuously attempted to design technologies that resemble nature. Weapons, such as spears and knives, used by primitive people were inspired by predators with sharp claws and teeth. Ancient Greeks saw sharp backbones of fish and made saws. They also used spider webs to stop bleeding when they saw how spiders used their webs to capture food. Why do humans study technology that resembles that of nature? It is because the excellent characteristics of these creatures enabled their survival. Recently, research on the application of biomimetic technologies has become increasingly active in various fields, including self-healing ability, environmental exposure resistance, hydrophobicity, self-assembly, and solar energy utilization

Various human senses are digitized through sensors, and biomimetic technology with sensory recognition mechanisms has permeated into our daily life in various ways. Examples include image sensors that replace eyes, speakers that replace hearing, and pressure sensors that replace touch. In many instances, these sensors are much more sensitive than our sense organs, enabling visualization of infrared and ultraviolet radiation and making ultrasonic sound discernible [68]. Furthermore, these sensors also provide new senses such as a sense of location and orientation enabled by the global positioning system (GPS) and gyroscopes, respectively [910]. However, there is surprisingly slow progress in the digitized detection of chemicals such as via smell and taste. This can be ascribed to the complexity of recognizing olfactory information and various technical limitations. However, interest in research on olfactory recognition mechanisms has been steadily increasing. Although our understanding of the mechanisms underpinning the sense of smell remains elusive, our limited knowledge is continuously being applied in various fields, such as the food, beauty, and health industries

For more detailed information about this study.....