Like many people, Alexander Patto was keen to move away from academia after his PhD. He wanted a job that would have a tangible impact on the world, so when an opportunity came up to investigate water testing in the developing world, he jumped at the chance. Together with a team of academics from the University of Cambridge, Patto, a biologist, worked on a simple way of testing bacterial contamination in drinking water.

“The current systems are very slow and complex,” says Patto. To get a robust result “there is a lot of manual sampling”, which can also lead to “a lot of human error”, he says. “What we’re trying to do is make it very, very simple, so that anybody can do a test, regardless of their skillset [and the] resources available, and still get a result that is scientifically robust.”

Water-borne bacterial infections are a leading cause of diarrhoea, which accounts for nearly 500,000 deaths in children under five each year.

One of Patto’s team had already released the designs for an open-source microscope, which can be produced anywhere in the world. “All you need is a 3D printer, the design files, some screws and a webcam,” he says. “It’s a way of getting high-performance equipment into very low-resource areas.”

The team developed a bespoke version of that microscope, to help speed up the detection of bacteria , plus a cartridge that simplifies sample collection, and image-recognition software, run on affordable Raspberry Pi computers, to study the growth of bacteria over time.

The cartridge system enables water testing to be done on site, with no need for a specialist, so communities can monitor their own water.

The team that developed the technology formed WaterScope, a not-for-profit based in Cambridge, in 2015. They have conducted one trial – in a refugee camp in Tanzania with help from Oxfam – and have two further trials planned.

Patto says these trials are crucial to ensure the system is designed for the people who will actually use it. “What we don’t want to do is have a technology push where we design something we like.” He points out that the system changed dramatically following their first trial: “We were trying to prioritise speed – but, when we were in the field, it turned out the users don’t really care about speed. What they care about is robustness and simplicity.”

When the scientists got back to Cambridge, they redesigned the system to ensure it was simple, robust and more portable. Their aim is to get test results in less than six hours.

The design process has been a case of constant refinement, says Patto, made possible by 3D printing. “We will go into the lab, we’ll print something out and test it. It’s very immediate. You have an idea in the morning, you validate it, move on, and refine it again.”

However they have encountered several challenges, including raising funding. “It’s always a battle between applying for funds and prototyping and trying to get the business stuff going,” says Patto. There’s also been the difficult switch from an academic to a business-oriented mindset. “In a PhD you are encouraged to explore in your thinking – you have enough time and resource to test loads of things. In a startup, however, you have so little resource, and so little time, you need to be extremely parsimonious with your goals. It took a long time for me to realise this.”

He has had some high-powered help along the way. On a business training course, he was mentored by the co-founder of Cambridge-based chip designer ARM, and he is now supported by the Royal Academy of Engineering, as part of an enterprise fellowship.

WaterScope is currently a small team spanning a number of different disciplines: from genetics to physics, chemistry, engineering and biology. It also employs two people in an innovation hub in Tanzania.

The water testing system is still in the prototyping stage. The startup is currently funded by the Royal Academy of Engineering fellowship, but Patto wants it to be a self-sustaining business by 2021. He says that might involve selling the technology in the developed world – to water-testing labs, for example.

There’s currently a variety of different methods used to test water quality. Businesses such as DelAgua and Palintest make membrane filtration tests. These look for ‘indicator bacteria’ that aren’t necessarily harmful in themselves but indicate that harmful pathogens could be present in the water. Vincent Casey, senior water and sanitation adviser at WaterAid, says the charity uses Aquagenx compartment bag tests, which are designed to be portable and simple to use.

However, it’s certainly an area that would benefit from further innovation, says Casey, especially in improving the precision of testing. Also, kits “take a little while to deliver results because of incubation” so speeding up that process would be useful, he says.