What is involved in research on IoT sensors

Internet of Water Flanders aims to better map water quality all over Flanders. To this end, imec develops sensors that are less expensive and have more capabilities than others that are currently on the market. A number of unforeseeable challenges in initial testing led to an improved plan for making the move from research to product.

The Internet of Water Flanders consortium has given itself four years to demonstrate that having a tightly-knit network of sensors for measuring water quality constantly may help policy-related decisions to be taken about water management. One important cog in the wheel of the system to be developed are the imec sensors that will be installed in the groundwater and surface water all over Flanders. The first prototypes were placed in the water at the end of year one of the project. With varying degrees of success, because the reality on the field often turns out to be at odds with the conclusions reached in the lab. Marcel Zevenbergen, program manager at imec, allows us to take a look behind the scenes and explains what’s involved in making the transition from a research environment to producing a robust application.

Can you briefly explain exactly what the IoW Flanders project is?

Water column in a laboratory setting, enabling the waterproofness of the parts used in the imec sensors to be tested to a depth of five meters.



Can you give us a practical example of an unexpected challenge?
Marcel Zevenbergen: “There have already been two significant learning moments for us in the past year. The first was right at the beginning when we placed the first sensors in the water. One of the connectors that we had bought in from outside appeared not to be as waterproof at greater depths over the longer term as the manufacturer had claimed in its specifications. The second unforeseen complication occurred about six months later. On that occasion, it was the cable from the sensor to the transmission station that was causing electrical interference and disrupting the readings taken by the sensor.”

But these sound like simple problems to solve…
Marcel Zevenbergen: “It’s not as easy as it sounds. Sometimes it takes a while to find the right solution. For the ‘leaking’ connector we installed a water column five meters deep in our laboratory to test the connectors. Would they stay waterproof over lengthy periods at this depth? And it took us ages and a lengthy investigation to solve the problem with the cable. We could only see a discrepancy in the reading and had no idea where it came from. So we had to investigate a great many parameters: the sensor itself, the environment it was placed in, the peripheral equipment – and so on. In the end it turned out that the cable was producing a small electrical signal. That, combined with the setting of our sensor and the salt concentrations in the water, was causing problems. Now we connect the cable differently with the sensor module and that appears to have solved the interference issue.

You are also part of a larger whole. The sensor is just one little piece of the IoW Flanders puzzle. When we place a sensor in the water, our partners are also standing by, ready to test their own part of the solution. And if one of these sensors doesn’t work properly then, you can’t test or develop these other components to a sufficient level either. So a trivial problem caused by a connector or cable can have far-reaching consequences for the other partners, as well as for the overall schedule.”

Has the timing of the project been adjusted?
Marcel Zevenbergen: “It’s true, we have encountered a small delay in relation to the original schedule. We are investigating whether we can use a small number of commercially available sensors on a provisional basis. These are more expensive and don’t provide all of the functions we need – but they will do for the time being. That way, the partners further along the chain can develop their own part of the solution (such as analyses and predictive models). We have also learnt that it is better to develop and test multiple versions of our sensor. For instance, we now have one version with a robust functionality for measuring salinization and another with an experimental functionality for measuring nitrates. For version 3, we may be able to wait until we have a robust nitrate measurement that we can combine with yet another experimental function or setting. This enables us to learn much more quickly, whereas we already have a certain functionality that is fully developed. Other sectors are also showing an interest for the technology we are developing for the IoW Flanders project. Our sensors may also be suitable for measuring the quality of drinking water or for monitoring bioreactors, for example for the production of medicines. That’s why it is also a good thing to have several versions that you can test in various other sectors.”


As program manager at imec and OnePlanet, Marcel Zevenbergen leads the work on the advanced sensors being developed for applications ranging from ways for promoting precision farming and measuring water quality to monitoring bioreactors. Marcel was awarded his MSc at TU Delft in 2005 and a PhD in 2009. He then began working at imec Netherlands, where he develops new sensor platforms in close collaboration with industrial partners.

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