Demcon Optiqua monitors Singapore’s drinking water

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Singapore’s national water agency PUB has committed to the operational rollout of Demcon Optiqua’s real-time drinking water monitoring system. In recent years, the two have worked closely together to develop the Eventlab solution, which is based on a patented optical lab-on-a-chip sensor with generic sensitivity to changes in water quality. Other drinking water companies, in Europe, China and the Middle East, have already expressed their interest as well.

The heart of the system is an integrated version of a Mach-Zehnder interferometer (MZI). This is a highly sensitive sensor for refractive changes. The refractive index is a useful generic indicator of water quality as any substance dissolved in water will change it. The sensor chip operates at a sensitivity level equivalent to parts per million (PPM) levels for a wide range of contaminants.

Demcon Optiqua’s patented optical sensor technology is based on an integrated version of a Mach-Zehnder interferometer (MZI). The basic layout consists of an input channel waveguide (1 in the figure) that splits into two identical branches (3): a sensing branch exposed to the water sample (4) and a reference branch. Both are combined again to form the output waveguide. The MZI works as an optical scale, measuring minute differences in refractive index as seen by the sensing branch versus the reference branch. Credit: Demcon Optiqua

Next to a network of sensors, the Eventlab system consists of infrastructure for data transmission and data analysis and visualization software. Data algorithms constantly analyze the network output for abnormal water quality changes. In case of an event – contamination or another change in the drinking water’s composition – the software issues an alert. This enables the drinking water company to immediately initiate action, for example, further analyzing the water.

Demcon’s support enables Optiqua to further expand the technology. “Drinking water safety is becoming more and more important worldwide and that has piqued our interest. We’re constantly looking for new markets where we can have a social impact with our technological expertise,” says Demcon CEO Dennis Schipper. “This is the reason why we’ve supported Optiqua for some time and last year made it part of our group. Another wonderful aspect is that the components for their technology are made at the University of Twente, where we had our start as a spinoff.”