Solid State Gas Sensor Technology

Since the advent of microelectronics and the emergence of microsystems in the late 1990s, a great deal of research has focused on the development of new sensors with low cost, small size, low power consumption and short response times. In the early 2000s, the interest in gas sensors for measuring traces of pollutants and toxic gases, or for measuring indoor or outdoor air quality, generated a great deal of research and development in both technology and materials science to meet this very high demand. Already in 2015, over 75% of gas detectors were portable.

It's important to remember that the World Health Organization (WHO) warned in 2019 that air pollution killed more than 7 million people worldwide. In France, that's over 40,000 deaths a year thought to be associated with air pollution (13 times more than the number of road deaths).

As this is a major public health issue, a number of regulations and standards have been introduced to assess both the population's exposure to pollution (both indoors and outdoors), and the actions taken by the various authorities to limit this pollution. On the other hand, it has become vital to take sufficient measurements to be as well-informed as possible about ambient air quality.

In France, in 2013, an action plan on indoor air quality was launched by the Ministries of the Environment and Health. This plan provided for short-, medium- and long-term actions to improve air quality in enclosed spaces, including:

• the creation of a consumer application to improve air quality in the home;

• implementation of air quality monitoring in certain establishments open to the public, including schools and nurseries;

• the implementation of monitoring systems at sites with specific pollution problems, such as underground railways;

• reducing exposure to the main sources of indoor air pollution (air fresheners: incense, candles, diffusers, cleaning products and furniture, etc.), in particular through information and labelling of these products;

• a gradual ban on the use of perchloroethylene in dry cleaners;

• publication of guide values for indoor air;

• support for the development of the indoor environment advisor profession.

National air quality criteria have therefore been defined in the Environment Code, with articles of law (L221-8 er R221-30) making it compulsory to monitor indoor air quality in certain establishments receiving a sensitive public such as children (leisure centers, crèches, day nurseries, nursery schools, elementary schools,...