‘Easier, cheaper, faster’: RSC winner develops low-cost, low-maintenance sensor that will overhaul water pollution monitoring

Mode Labs’ self-cleaning, miniaturised water sensor requires no infrastructure, limited maintenance and lower costs

July 27, 2023
© Alex Ramsay / Alamy Stock Photo
© Alex Ramsay / Alamy Stock Photo

Dean James and his colleagues have been working on a piece of new technology for decades—first at the University of Oxford and now as a spin out company called Mode Labs Ltd. “Somewhat unusually for academic scientific research, once the original idea... was spawned, almost everything we tried to do worked,” James tells me. “Scientific development is usually a lot more of a fickle creature than this, so we knew we were onto something special.”

This month, with their scalable and easy to deploy water pollution sensors, the team took the top spot in the Royal Society of Chemistry (RSC) Emerging Technology Competition’s environment category. “We were ecstatic—but also somewhat surprised,” says James. “It was a strong field of contenders, with some amazing technologies and some very impressive pitches.” James has always tried to be as involved with the RSC as possible, as it has been “incredibly supportive throughout my entire professional career as a chemist”. 

The winning product was a “low-cost, portable, real-time method for quantifying and speciating pollutants in natural waterways”. The devices, which will be deployed in rivers and lakes, measures levels of total phosphorus and ammonia, which are used to assess water quality. The aim is to help reduce the environmental impacts of sewer overflows, agricultural run-off and illegal dumping through targeted intervention. 

Currently, the “backbone” of the water monitoring operation is manual samples taken from the river and shipped across the country to specialised laboratory facilities. “This process is costly, slow, and carbon-intensive, and the data produced is a single-snapshot of a constantly evolving situation, meaning that pollution ‘events’ are either missed or poorly understood,” says James. Those in the water industry needed a device that was affordable to buy and run, and that could cover all the pollutants of interest. Mode Labs’ devices, then, will “allow water companies to meet their obligations under the new Environment Act 2021 with reduced capital and operational expenditure, reducing costs for the public consumer.”

These devices were created using novel “optical microcavities” to provide enhanced sensitivity to absorption measurements. “An optical cavity is any device that traps light in a confined region and causes it to bounce back-and-forth across the same area,” explains James. “We use specially crafted micromirrors with extremely high reflectivity coatings that trap light within a micron-scale region for over 10,000 reflections.” This approach, he says, increases the sensitivity of optical absorption measurements by 10,000-fold.

This has allowed the team to develop smaller, more cost-effective devices with significantly reduced power requirements, no need for infrastructure and self-cleaning and maintenance cycles.

For Mode Labs, the competition was not only a “morale booster” but an “incredible opportunity to reflect on everything the team has achieved so far, and to discuss plans for the future with industry leaders and other entrepreneurs on their own technology commercialisation journey,” says James. “As well as being a genuinely enjoyable process, it’s a chance to challenge assumptions, receive constructive feedback, grow your network outside of your usual spheres, and an excellent opportunity to increase the exposure of chemistry-led companies.”

Perhaps most importantly, though, the £25,000 prize pot from the competition has served as a “valuable contribution” towards the company’s second round of field trials, which will “demonstrate our technology and make our devices even easier to deploy and maintain”. Beyond that, James says, “the recognition from such a prestigious institution will help us in our continuing recruitment of highly skilled chemical scientists, by demonstrating our commitment to innovation and high-quality science.”

The recognition couldn’t have come at a better time. “Now more than ever we need to make it easier, cheaper and faster to understand what’s going into our waterways, and what we can do about it,” James says. “With our novel optical microcavity technology and custom microreactors, Mode Labs are setting out to do just that.”