DAC102021

48 n WATER October 2021 www.drivesncontrols.com Motor-driven lab predicts changes in water quality A s the impact of climate change and land use continue to harm aquatic environments, it is becoming increasingly important to measure and monitor changes in water quality. To help predict future changes in water quality, Dublin City University (DCU) Water Institute has developed mobile laboratory that produces real-time data and delivers quick results, as well as reducing the risk of contamination. DCU is part of Beyond 2020, a research cluster consisting of six Irish and UK institutes examining new technologies for monitoring water environments to understand the role of aquatic ecosystems in a changing global environment. The mobile lab project was sponsored by the Irish Marine Institute and involves studying freshwater sites where the quality is good and monitoring any changes that could impact the ecosystem. The team – led by Professor Fiona Regan, and including Joyce O’Grady, a DCU PhD student and Dr Nigel Kent, assistant professor in the DCU’s school of mechanical and manufacturing engineering – developed a sensor for real-time detection of low phosphate levels in catchment areas. Phosphates are a measure of nutrient pollution and control the pace at which algae and aquatic plants develop. To mix and measure the water sample and the reagent fluid, the team developed a centrifugal microfluidic disk that acts as a mobile lab, capable of performing six tests per disk. For the lab to operate as designed, it was critical for the disk to spin faster than 5,000 rpm to drive fluids towards the outside of the disk for at least 60 seconds. At the measurement stage, it was also necessary to index the disk through 60-degree increments with a precision of better than 1 degree. To achieve the necessary precision and speed control, the team chose a 22mm- diameter DC motor and three-channel encoder from maxon. The motor’s shaft was modified to extend its length and to provide a flat edge to mount the disk. The DCX motor and encoder form part of an integrated system that needed to minimise sample handling to reduce the risk of contamination. The sensor has now been validated, and studies are continuing in other areas. One study has been completed on the River Liffey, and another is due in a lower catchment area. To complete the fifth year of the project, the system will be replicated for four more studies. “Industry 4.0 is finding its way into many different industries,” comments Dr Kent. “The kind of system that Joyce is developing will be prevalent; autonomous sensors that you can leave out and get real-time feedback on the state of rivers or lakes will play a huge role in areas like Agriculture 4.0. “For example,” he adds, “the interconnected nature of technology, using drones for smarter spraying, reduces water run-off, which helps prevent water pollution and protects our drinking water resources. This will be the industry focus over the next decade.” When developing their lab, the DCU team took advantage of maxon’s Young Engineers Program (YEP) aimed at students and start- up companies, which supports innovative projects involving electric drive systems. It offers technical support, products at discounted prices, and promotional opportunities. “I assumed pricing would be a barrier, but the YEP made it a no-brainer,” says Kent. “I had previously only considered maxon products in final applications, but not for prototyping.” n Researchers in Ireland have developed a mobile laboratory for monitoring water quality in river catchments. A key component in the lab was a small DC motor that had to be able to spin at high speeds and to provide precise indexing capabilities. The mobile lab has been used to study the quality of water in the River Liffey, which flows through Dublin The DCU portable laboratory includes a disk that is spun at high speeds to drive fluids towards the outside