Overview
A gas sensor is a transducer that detects changes in the volume fraction of a gas and converts those changes into electrical signals. It can be used to detect the presence of specific gases within a given area and/or to continuously measure gas concentration. Detection principles and sensor technologies vary widely and include electrochemical sensors, nondispersive infrared (NDIR), metal oxide semiconductor (MOS), catalytic combustion (pellistor), photoionization, gas chromatography, photoacoustic spectroscopy (PAS), Fourier-transform infrared (FTIR), chemiluminescence, and quartz crystal microbalance (QCM). Selecting the appropriate technology for a target application requires a comprehensive evaluation of sensor sensitivity, selectivity, power consumption, cost, and size.
Market analysis in the report "Environmental Gas Sensor Technology and Market - 2023 Edition" forecasts the global gas sensor market to grow to $9.5 billion by 2034, with a compound annual growth rate (CAGR) of 6.6% for 2024–2034. Typical application areas include industrial, medical, consumer electronics, HVAC, transportation, and atmospheric environmental monitoring.
Common Gas Sensor Types (Detection Principles)
MEMS technology has enabled miniaturization of gas sensors and expanded their consumer applications, accelerating the adoption of gas sensing in everyday life. Leading sensor manufacturers have introduced MEMS-based devices such as: (1) indoor air quality sensors that detect total volatile organic compounds (TVOC) and estimate equivalent CO2 (eCO2); (2) outdoor air quality sensors that detect nitrogen dioxide (NO2) and ozone (O3); and (3) gas sensors for smart refrigerators that detect compounds related to food ripening or spoilage.
For example, Siemens Appliances released a smart eNose refrigerator that integrates the Bosch Sensortec BME688 micro four-in-one gas sensor. The BME688 can measure gases including VOCs, volatile sulfur compounds (VSCs), carbon monoxide, and hydrogen, as well as humidity, temperature, and pressure. The device uses artificial intelligence models to implement electronic nose functionality.
Electronic Nose System Components
An electronic nose system consists of two key elements: (1) a gas sensor array for chemical detection, and (2) algorithms that provide the analysis models used within the system. To address challenges in detecting complex and trace gases, researchers integrate multivariate analysis techniques into the algorithm component of electronic nose systems. These techniques improve selectivity in multivariate scenarios and mitigate limitations such as sensor cross-sensitivity and poor selectivity.
In recent years, the combination of sensor arrays and machine learning algorithms has driven applications in home appliances, environmental monitoring, food safety, and medical diagnostics, accelerating the maturation of electronic nose technology. Academic literature shows growing clinical applications of electronic nose systems, including early cancer screening, bacterial pathogen identification, superficial wound microbiology, COVID-19 detection, and Helicobacter pylori breath analysis.
Air Quality and Monitoring
Air quality is a major global health concern. In many regions, air pollution remains severe. The World Health Organization recognizes air pollution as a major risk factor for noncommunicable diseases, estimating that it accounts for 24% of adult deaths from ischemic heart disease, 25% of stroke deaths, 43% of chronic obstructive pulmonary disease deaths, and 29% of lung cancer deaths. Air pollution not only threatens public health, it also damages natural and built capital and hinders economic growth. Because air pollution crosses borders, improving air quality requires sustained, coordinated actions by governments to pursue sustainable transport, more efficient and renewable energy production and use, and improved waste management. These drivers have increased the use of gas sensors in environmental monitoring and control, covering outdoor atmospheric environments as well as enclosed indoor and in-vehicle spaces.
Market Trends and Applications
Automotive powertrain, industrial process control, environmental monitoring, and HVAC continue to account for major shares of the gas sensor market. Driven by higher expectations for air quality and increased demand for health-related products since the COVID-19 pandemic, gas sensors are increasingly used in smart home products such as air purifiers, in wearable devices, and in Internet of Things (IoT) devices, enabling consumers to monitor indoor and outdoor environments.
In electric vehicles, gas sensor solutions are expanding their role: (1) battery health monitoring systems use gas sensors to detect gases released prior to thermal runaway, such as CO2, CO, and VOCs, along with temperature and pressure indicators. Measured signals can be transmitted via CAN bus to the battery management system to help prevent fires and explosions; (2) cabin air quality sensors help maintain comfort and safety. For example, the GAC HYCAN 007 integrates cabin air quality sensing that detects carbon monoxide, hydrocarbons, and nitrogen oxides, and can automatically control HVAC recirculation to improve in-cabin air quality.
