• Samu-Pekka Ojanen

Network of sensors for real time air pollution measurement

More and more people live in an urban environment than ever before, which means that more and more people get exposed to toxic emissions and air pollutants on a daily basis.

This leads to health problems and early deaths, which are caused by these emissions. In fact, WHO estimates that air pollution kills around seven million people per year.

To put that into perspective, that amounts to nearly 130% of the Finnish population dying every year. To target our measures to control and reduce these toxic emissions, we need data, we need to be able to measure these emissions – preferably in real-time.

What if you could have an integrated sensor on every car measuring air pollutants in real-time? What if these sensors would form a network that was connected to the internet of things, giving you access to this real-time air pollution map? What if anyone could access this data, e.g. from their smartphone?

This kind of vision would require integrated sensors that were reliable and had a long lifespan. They should not consume much power so that they would not drain the battery of the car, or any other device that they could be integrated into. They should be affordable so that they would not have a noticeable effect on the price of the device. Finally, they would need to be compact, so that you could fit them into existing devices.

Developed tehcnology of integrated sensors

Optics has offered various solutions to tackle this problem. However, the problem with the current optical sensors is that they are too bulky and expensive to be able to widely adopt into automotive applications and consumer electronics.

Fortunately, the technology to build these types of integrated sensors is becoming a reality, in the form of photonic integrated circuits, which are chips that manipulate light on a very small scale. In fact, you could fit one on the tip of your finger. Because these chips do not have any moving parts, they are very reliable, low power, and robust. They could also be mass-produced, which makes them a very cost-effective solution.

Our research focuses on building such light-based integrated sensors by combining the state-of-the-art light source technology from our research group, ORC at Tampere University, and the unique silicon photonic integrated circuit platform from VTT. The proof-of-concept of application is done in collaboration with Vaisala, who is a global leader in environmental and industrial measurements. This is a unique and strong collaboration of expertise in Europe, that combines the strong points of both academia and industry.

Our technology could be used to build various sensors, measuring e.g. greenhouse gases and toxic emissions. In addition, the underlying technology could have wider application in medical technology or ICT, with a strong impact, as the one microelectronics has had in the past few decades.

Samu-Pekka Ojanen

Doctoral researcher