SciTech Europa looks at why research into environmental sensors is important and some of the recent developments in the field.
The growth of Europe’s cities, agricultural activities, and manufacturing has led to an increase in air, water, and ground-based pollutants which impact the environment and he European Commission continues to implement a policy framework which prioritises the reduction of these pollutants.
The environmental sensors industry will play a vital role in the transition to the circular economy in Europe and is essential to achieving the European Commission’s aim for greater sustainability to make Europe a smarter, healthier, and more efficient society.
The EU framework for addressing pollutants
The Environment Directorate General of the European Commission (‘DG Environment’) was set up in 1973 to ‘protect, preserve and improve Europe’s environment for present and future generations’.
Some of the salient aims of DG Environment include keeping air and water clean and helping the EU move towards a sustainable economy. Environmental sensors are crucial to achieving the sustainability and environmental aims of the EU Commission because environmental sensing will provide the evidence to enable sustainable regulation and policy choices.
According to DG Environment, the human toll for poor air quality is worse than for road traffic accidents. Poor air quality is the number one environmental cause of premature death in Europe and affects quality of life by causing asthma and respiratory problems. Economically, this leads to lost revenue from working days and high healthcare costs, especially for the most vulnerable groups who are worst affected by the health issues caused or exacerbated by poor air quality.
The 2018 ‘Clean Air for All’ report by the European Commission stated the continued need to monitor the presence of air pollutants such as ground level ozone, particulate matter, nitrogen oxides, dangerous heavy metals and several other pollutants which have been frequently exceeded by EU Member States.
Europe depends on soil, yet its farming activities are making soil vulnerable to erosion, covering fertile soil by concrete as cities grow, and contaminating some areas of soil with lead, oil, and solvents. These issues can cause groundwater pollution, which damages human health and other organisms, and poses a risk to food quality because many crops are grown in polluted soil. The vulnerability of soil is expected to increase as climate change increases global temperatures and heavy rain fall and flooding occurs more frequently.
Monitoring water quality can give researchers and policymakers salient information on the impact of human activities on ocean acidification, seasonal fluctuations, and extreme weather events, which is essential for evidence-based decision making on sustainable choices and regulatory policies.
On 1 February, a revision to the EU policy framework for water quality was proposed. Some of the key focuses of the framework include empowering authorities to deal with the risks to water supply, empowering consumers by providing them with valuable information about the efficiency and effectiveness of water suppliers, contribution the transition of the circular economy by managing drinking water sustainably and improving access to safe drinking water for EU citizens. The EU Water Framework Directive states that: ‘Water is not a commercial product like any other but, rather, a heritage which must be protected, defended and treated as such.’
Developing materials for environmental sensors
There are various combinations of materials which can be used as environmental sensors for different purposes, and sensors can detect temperature, humidity, water, air flow, and chemical composition to name a few.
Porous materials such as zeolites and metal-organic frameworks (MOFs) are thermally and chemically durable. The porosity of these materials means that they can be used for environmental purification, gas absorption, and environmental catalysis. These materials have the potential to speed up sampling for diagnostics, reducing the time and cost.
Materials research can also advance water quality monitoring in the ocean. Researchers at Brown University, USA have recently showed how composite materials can be used as a sensor in the ocean during an oil spill.
Graphene oxide can be added to hydrogel materials from alginate, a natural seaweed-derived material currently used in biomedical applications. A 3D printing method can then be used to make the alginate-GO structure durable and intricate which are more resistant to fractures than alginate by itself.
The material can become stiffer or softer dependent on how it is treated. This means it could be used for smart materials that are able to react to their surroundings in real time, an application which would align well with the European Commission’s focus on developing smart cities for environmental sustainability and increased quality of life.
Another potential application for these materials as an environmental sensor includes ocean monitoring, where the sensor could continue taking readings in the ocean during an oil spill.
Graphene-based sensors have shown potential for environmental monitoring of NO2. Researchers at the National Physical Laboratory (NPL), the University of Surrey, and University of London (UK), along with Chalmers University and Linköping University, Sweden, have demonstrated environmental monitoring of ultra-low concentration NO2 in complex environments using the graphene-based sensors. The team argue that the potential for small, highly sensitive, low-cost sensors have a massive potential for monitoring air quality. Currently, air quality measurement is expensive, but a dense monitoring network could be enabled using the distribution of low-cost sensors in large cities. This could be an effective way of enforcing environmental regulations aimed at improving health and quality of life.
Similarly, the researchers Arindam Phani, Thomas Thundat and Vakhtang Putkaradze at the University of Alberta, Canada, have developed a new sensor. The new sensor uses a vibrating nanowire ‘brush; to interact with outside air and has potential uses in chemical, defence and environmental applications.
Real-time optical particle counters are on the air quality monitoring market, as devices which use absorption or light scattering. Usually the method used is that the air particle travels through a light source and causes scattering of the light. This is then detected by a photodiode which allows for conversion into a particle count and values of mass concentration, speeding up monitoring of certain particulates in the air.
The future of the environmental sensors industry
The environmental sensors industry is a rapidly growing market, and the sensors being developed have important environmental applications such as monitoring water and air quality.
Garner Insights recently reported that the technology market for the environmental sensors industry is entering a new era of huge demand in 2018.