Published 2019-03-12

This post is also available in Swedish

Sensor measures nitrogen oxides in street light poles

Another new product has seen the light of day in Mistra. An optical nanosensor for measuring nitrogen oxides has been developed by the Gothenburg company Insplorion. The sensor is now to be integrated into street lighting — an important step towards a commercial product.

Air pollution is a worldwide problem. Today, fixed and costly measuring stations or satellites are our main means of monitoring air quality. The Gothenburg firm Insplorion, with its optical nanosensor, aspires to make environmental monitoring simultaneously cheaper and more refined. The aim is, by integrating its sensor into existing infrastructure, to measure air pollution on literally every street corner.

‘In Gothenburg, for example, there are five or six environmental measuring stations, each costing around half a million kronor. Our optical nanosensors can offer the same measurement accuracy, but at considerably lower cost. The sensors are tiny and can be attached to every street light pole in every town and city. This makes for higher-resolution results in urban areas,’ says Patrik Dahlqvist, Insplorion’s CEO.

In about 2000, researchers at Chalmers University of Technology began to develop a new type of measurement technology based on an optical phenomenon known as a ‘plasmon’. This arises when metal nanoparticles are illuminated and capture light of a particular wavelength.

In 2010, Insplorion was founded to commercialise the technology.

The company already has some 20 academic clients around the world that utilise the technology in materials science and biotechnology research. But the great commercial potential of the sensor, according to Dahlqvist, lies in two of its features. First, the sensor can be adapted to measure various substances. Second, it can be tiny in size with retained measurement accuracy.

‘The nanoparticles have a capacity to amplify measurement signals. So instead of a big, expensive spectrometer, it’s enough to use an LED source and a tiny detector.’

The company is developing the technology for two main applications. One is a battery sensor for improved capacity utilisation in electric vehicle batteries. The other is a sensor to measure the atmospheric concentration of various pollutants. This air-quality sensor has been developed in the past few years with Mistra Innovation’s support (in the PAQSens project; see Facts, below). The project budget has, in particular, funded a Chalmers postdoctoral researcher who has developed and miniaturised a sensor to measure nitrogen oxides.

Insplorion has shown, partly with its installations in Gothenburg, that the sensor works. In the course of 2019, the company will take the next step in its commercial development. At year-end 2018, jointly with the company Leading Light, Insplorion presented a collaboration to develop smart lighting systems.

‘We’ve tested the sensor we developed in Mistra Innovation, so we know it works outdoors. Now we’re leaving the lab and taking the final step towards commercialisation in cooperation with Leading Light.’

The first phase in this collaboration is physical adaptation of the sensors to enable them to be mounted on street lights. Together, the two companies will then engage in marketing and sales in Sweden and abroad. Dahlqvist hopes the first commercial installations will be commissioned in Sweden during 2019.

‘The agreement is important. It enables us to show that we have a viable product, commercially as well. Once we’ve done this, the road ahead will be clear. First, we’ll be able to get major players and partners on board; second, we can integrate the sensors into other technical infrastructure, such as roads,’ says Dahlqvist.

If the collaboration with Leading Light turns out well, the road is open to further expansion outside Sweden too, Dahlqvist adds. Future sales in Asia and South America, in particular, are the goal. To date, the sensors have been adapted to measure nitrogen oxides, but can be developed to measure other air pollutants, such as sulphur dioxide, carbon monoxide and ozone as well.

The customers are mainly municipalities and other agencies that monitor the environment and are responsible for fulfilment of environmental objectives. But Dahlqvist also cherishes the hope that, in the longer term, the sensors can be personal: they could, for example, be incorporated in a pocket-sized device or mobile phone.

‘If we’re to sell pocket sensors, we’ll have to cut the price further — below 1,000 kronor. And that’s entirely possible with our technology, but we’re not quite there yet,’ Dahlqvist says.


Purpose: to develop a Portable Plasmonic Air Quality Sensor (PAQSens) for measuring air pollution, primarily nitrogen oxides

Partners: Insplorion and Chalmers University of Technology

Budget: SEK 6.1 million, including Mistra funding of SEK 2.8m.

Time schedule: 2016–19

Learn more about the project on Mistra Innovation’s website (in Swedish)

Demo Internet of Things project (LoV-IoT)

Text: Henrik Lundström