Microelectromechanical systems (MEMS) and screen-printing techniques open the door to miniaturised gas sensors and enable the integration of such gas sensors into many consumer devices, such as mobile phones and wearable devices (as shown in image 1). We envision a rapid growth in the use of these miniaturised sensors, making them more accessible in our daily lives. This article is drawn from report "Environmental Gas Sensors 2020-2030". This report has highlighted the technology innovations toward miniaturised advance gas sensors mainly targeting emerging markets.
Image 1: comparison of traditional gas sensors and miniaturized gas sensors. Source: IDTechEx Report, "Environmental Gas Sensors 2020-2030".
The common gas sensing technologies available in the market for consumer applications depend on technologies such as metal oxide semiconductors (MOS), electrochemical detection (EC), photoionization (PID) and infrared (IR), a comprehensive comparison can be found in table 1. Metal oxide sensors have been most successfully miniaturized using MEMS technology. Several traditional sensor manufacturers have expanded their portfolios to produce MEMS based sensors as well as a number of new companies entering the market. Benefiting from the low cost, low price and the capability for large scale manufacturing, MEMS based MOS sensors are adopted by the consumer electronic market rapidly, such as smart devices, novel automotive gas sensor, breathalyser and more. However, for the applications require higher sensitivity and selectivity, such as smart city projects, electrochemical gas sensors are usually preferred. SPEC successfully uses screen printing technology to miniaturise EC sensors.
Table 1: Benchmark of common gas sensing technologies. Source: IDTechEx Report, "Environmental Gas Sensors 2020-2030".
Most recently, substantial effort has focused on developing alternative devices with higher selectivity and resolution. The electronic nose (eNose, or artificial olfaction) is one of the main research directions. It is a gas sensor with multiple sensing elements with the capability of reproducing human senses using sensor arrays and pattern recognition systems (such as artificial neural network). Field Asymmetric Ion Mobility Spectrometry (FAIMS) is another promising technique based on ion separation in gaseous phase due to different ion mobilities under an electric field based on their size, mass and shape. More innovation of gas sensing technologies can be found in the report "Environmental Gas Sensors 2020-2030".
These advancements of gas sensing technologies open the door for multiple new markets. Gas sensors are increasingly integrated into IoT ecosystems to monitor environment air quality, such as inside wearable devices, smart city projects, smart home electronics and automotive. Another key trend to utilise advanced gas sensing technology is the breathalyser, which aims at non-invasive diagnostics via detecting biomarkers from the exhale breath. The development of novel breathalysers that are qualified for clinical level diagnostics will be one of the key strategies in the coming years for medical and pharmaceutical companies. The total market is expected to be over 3.8 bn USD by 2030.
The report "Environmental Gas Sensors 2020-2030" gives a comprehensive analysis on the recent gas sensing innovations as well as details on the key players, future opportunities and challenges in this growing industry.