Light for climate protection: Photonics as the key to better air and less particulate matter
One of the most important challenges facing society today is climate protection. Light-based innovations can make a significant contribution to this. As "green photonics", they can increase air quality, among other things. Photonic applications are used mainly to monitor particulate matter emissions or measure the concentration of particulate matter., Cornelia Ehrler
Already today, studies have demonstrated that photonics and optical technologies can make a positive contribution to improving global sustainability and promoting climate protection. According to the German industrial association, Spectaris, the use of light-based technologies have already saved around 1.1 billion tonnes of CO2. They expect this to increase to three billion tonnes by 2030. This corresponds to approximately 11 percent of the agreed CO2 reduction targets of the Paris Climate Agreement.
Photonic-based products and applications such as laser, sensor and optical systems can support sustainability in the most diverse areas. Optical technologies are used to improve the quality of air, for example. This is not only relevant when it comes to discussions on particulate matter pollution and driving restrictions: The pollution of air quality by particulate matter has been the focus of public debate for several years now. Many regions in Europe are currently failing to meet air quality targets set by the EU. What is clear, however, is that emissions and air pollution greatly affect the health of citizens – a hidden risk that can lead to serious illnesses.
Jenoptik wants to contribute to promoting worldwide climate protection with photonic products. Two examples from the wide range of products illustrate the benefits for road traffic.
What is particulate matter exactly?
- Particles with a diameter of less than ten micrometres are referred to as fine particulate matter.
- Fine particulate matter is generally caused by emissions from motor vehicles, industrial processes or chimneys
- The problem: Fine particulate matter does not simply sink into the ground but remains in the atmosphere for some time.
- The smaller the particulate matter, the more harmful to health
- Particles smaller than 2.5 micrometres can penetrate into the human lung
Green cameras for less particulate matter and a cleaner air
For example, four roads were identified in Wales in 2019 in which the motor vehicle emissions had a direct impact on the air quality. In order to improve the situation in these targeted areas, the prescribed speed was reduced to 80 km/h (50 mph) along key road sections with poor air quality readings. SPECS cameras from Jenoptik were installed to monitor the new speed limits. These determine the average speed of vehicles that drive past, through reading the vehicle’s number plate at both an entry and an exit location, thus providing a very accurate speed measurement over a distance.
As a rule, reducing the speed limit does not necessarily mean that drivers comply with it. However, The Welsh Government knew that these cameras are highly effective in achieving compliance; many installations have proved that drivers always comply with speed limits in locations where SPECS cameras have been installed, driving at a uniform speed, so emissions are reduced.
Initial reports show that this approach is working exactly as was hoped. This means that acceleration and deceleration are avoided and the driver drives at a constant speed over a long section of road. This driving style is considered safer, smoother and environmentally friendlier. This means that the legal requirements of the Paris Climate Agreement can be better fulfilled and public health is supported. An additional advantage of this driving style is a significant reduction in the number of road casualties, due to steadier, safer flows.
The cameras used for this project have been designed in bright green to make it clear to drivers why they are being monitored. This colouring has proven to be helpful in improving understanding and acceptance.
Particle sensors in use for less particulate matter and better air quality
However, pollutants are not just found on the roads but also in the interiors of vehicles. The solution to this could be photonic systemsbecause these provide car manufacturers and suppliers with the possibility of improving air quality in the interior of the vehicles.
So-called particle sensors are being used for this. They can reliably and accurately measure the smallest concentrations of fine particulate matter less than 2.5 micrometres diameter in the vehicle environment. Jenoptik developed a laser-optic subsystem for particle sensors like these.
The high accuracy of the sensors is achieved by specific precision polymer optics and highly accurate adjustments of the optoelectronic system.
In this scenario, one sensor is responsible for monitoring and optimising the air quality in the vehicle. This is achieved by automatic control of the air supply on the one hand and, on the other, efficient air filters improve the air quality. A second particle sensor measures the concentration of particulate matter in the vehicle environment. Moreover, further digitalised application cases can also be realised, including route planning that takes into consideration the local air quality, for example.
The high measuring accuracy is the decisive point, as the finer the particulate matter, the more it poses a risk to health. Fine particulate matter with a size of less than 2.5 micrometres can penetrate deep into human lungs, where it builds up and poses a health risk.
But how, exactly, is the particle sensor constructed? Laser diodes and polymers form the heart of the sensors and are responsible for the precise measurements. Both are combined with a high-precision five-axis adjustment to form a laser-optical complete system. This allows us to ensure the high measuring accuracy of the sensors.
Jenoptik's core expertise includes developing, manufacturing and assembling precision optical systems and automated series production, providing automotive quality. Components and systems to make traffic systems safer worldwide are also developed, produced and marketed.
About Cornelia Ehrler
Cornelia Ehrler has been working in Jenoptik’s Corporate Communications since 2010, primarily for external communications and initiatives which help Jenoptik develop into a focused photonics group. As press officer for all Jenoptik topics relating to road traffic safety, she supports the Light & Safety division in communicating orders and projects. A graduate in English Studies, she has a penchant for English literature and culture, particularly from the Celtic Fringe.