It was a team effort that brought start-up Firefly Sensing to life, emphasize its CEO Mildred Cano and CTO Don van Elst. ‘The core technology underlying our company combines the work of multiple researchers in TU/e’s Photonics and Semiconductor Nanophysics group on small photonic sensors and multispectral readout systems.’

The sensing system they are commercializing consists of three elements: a photonic sensor that changes its reflection spectrum depending on the liquid being analyzed, a light source to illuminate the sensor, and a readout unit that captures the sensor’s spectral fingerprint. The breakthroughs enabling this application are a readout approach based on an array of photodetectors, and a dedicated estimation algorithm to interpret the recorded signals. 

‘We measure the refractive index of the liquid,’ Cano and Van Elst explain, ‘since this is a parameter that can be related to concentration of ingredients such as alcohol or sugar. The food and beverages sector has been monitoring this for years, albeit with either devices that require sampling of the fluids during production, or in-line systems that can measure in real time but are large, and very expensive. Our solution is smaller, more versatile, more affordable and more automated. It provides real-time measurements exactly where they are needed: directly in the process, without any sampling.’

This first prototype has been demonstrated to work on a variety of substances in the lab. Aided by a NWO Take Off Phase 2 loan, the company is now taking its sensor to a real environment. ‘We will be testing our technology directly in real production environments,’ Cano explains. ‘That is the ultimate test case,’ Van Elst adds, ‘since on-site, we are not working in a particularly controlled environment.’ ‘From the pilots, we hope to learn about the robustness of our system,’ says Cano. ‘For example: can our sensor deal with temperature differences, and what happens if the sensor gets dirty?’

Another open question has to do with the ideal design, Cano says. ‘Originally, we had mounted the sensor directly on top of a glass fiber. But our industrial partners indicated that they did not want to have to replace the entire fiber if anything is malfunctioning. So, for now we have inserted the sensor in a separate flow cell. In the pilots, we want to determine if this is indeed the best way to go.’

The dream is to bring this promising technology into the world, the entrepreneurs state. ‘We want to help industries become more sustainable and improve their process quality. We’ve worked hard to get here, and we are confident that we will be launching our first product in the near future.’