The Royal Academy of Engineering’s Africa prize, now in its sixth year, is the continent’s biggest award for engineering innovation. Sixteen African inventors from six countries – including, for the first time, Malawi – have been shortlisted to receive funding, training and mentoring for projects intended to revolutionise sectors ranging from agriculture and banking to women’s health. The winner will be awarded £25,000 and the three runners-up will receive £10,000 each.

This year’s inventions include facial recognition software to prevent financial fraud, a low-cost digital microscope to speed up cervical cancer diagnosis, and two separate innovations made from water hyacinth plants. Four inventors spoke to the Guardian about their innovations and their plans to change Africa for the better.

Ghana: tackling online fraud

Identity fraud and cybercrime are big business in Ghana, where financial institutions spend about $400m (£306m) a year verifying their customers. For Ivory Coast tech entrepreneur Charlette N’Guessan, 25, who led research into what technology Ghanaian banks were using to prevent fraud, the cost was far too high.

‘Fraudsters are getting smarter every day’: tech entrepreneur Charlette N’Guessan. Photograph: James Oatway/Africa prize for engineering innovation

“We live in the age of data and fraudsters are getting smarter every day,” says N’Guessan, one of six women shortlisted for the prize. “Online fraud is very high in Africa, and although financial institutions spend a lot of money trying to fix it, they don’t have a real system to prevent it. I thought: ‘I’m a software engineer, let’s talk to banks and see what we can do about this.’”

Along with two friends she met while studying a tech training programme offered by the Accra-based Meltwater Entrepreneurial School of Technology, N’Guessan developed software that uses facial recognition and artificial intelligence to verify identities remotely. Their invention, Bace API, replaces existing methods such as two-step verification or password memorisation. Instead, live images or short videos taken on phone cameras are used to detect whether the image is of a real person, or a photo of an existing image. It then matches the picture or short video to either a pre-saved reference photo, or the person’s government-issued identity documents.

“If it matches, it means the person accessing the services is the same person, it’s not a fake account or a robot,” says N’Guessan. “We have to make sure it’s a human.”

Bace API software matches live imagery with stored photos or identity documents. Photograph: James Oatway/Africa prize for engineering innovation

Bace API is currently being used by two local financial organisations. N’Guessan plans to roll out services to more clients within the next three months, primarily in Ghana and Nigeria. She also aims to partner with universities to create a database of students who don’t currently have government-issued ID cards, helping them to gain access to financial services.

“There are so many universities in Ghana, yet so many students miss out on being able to open bank accounts simply because they don’t have passports or driving licences,” she says. “With Bace API they’d be able to use their university ID cards instead. Students would benefit and businesses would tap into a whole new market as well.”

Uganda: cervical cancer screening

In 2016, William Wasswa was preparing medical equipment to help pathologists manually analyse pap smears for cervical cancer. The complicated process was time-consuming and prone to error, and wasn’t helped by long queues of female patients waiting outside the lab for their test results. The experience gave Wasswa, 30, a biomedical sciences assistant lecturer at Uganda’s Mbarara University, an idea how to improve things.

“Cervical cancer is the leading cause of death among female cancer patients in Uganda, and I’ve lost family and friends to the disease,” says Wasswa. “But misdiagnosis is very common. I said to myself: ‘This process could be sped up and improved by using artificial intelligence.’”

‘I’ve lost family and friends to cervical cancer’: Dr William Wasswa. Photograph: Brett Eloff/Africa prize for engineering innovation

An estimated 100,000 women are diagnosed with cervical cancer every year in sub-Saharan Africa, and 62% are expected to die if they don’t receive treatment. Women who are HIV-positive are five times more likely to develop the preventable disease, which is caused by the human papillomavirus (HPV), the world’s most common sexually transmitted infection. Women in Uganda are disproportionately affected by HIV, accounting for 59% of the 1.3 million adults living with the disease.

Wasswa was inspired to transform the entire process of cervical cancer screening in Uganda. Instead of relying on low-cost microscopes – which, though ubiquitous in labs across the nation, are unable to digitally store samples for analysis – he developed a digital microscope slide scanner to study high-resolution cervical cell images from pap smears, using a 3D printer to make the parts. The device has very good results and only costs a quarter of the price of commercial microscopes, he says.

He then turned his attention to the poor management of patients’ records, none of which are digitised. Again, Wasswa designed specialist software, this time to assess the likelihood of a patient contracting cervical cancer given her risk factors, as well as a separate system for managing and archiving patients’ records using AI.

“Right now, there is almost no follow-up for patients, no reminder when they should come in for their next smear, but our platform also provides telemedicine support,” he says.

The digital microscope slide scanner has performed well and is 75% cheaper than commercial microscopes. Photograph: Brett Eloff/Africa prize for engineering innovation

Finally, Wasswa created a tool to diagnose and classify cancerous images and plans to establish a repository of images that can be used for cancer research. Overall, his system has had 90-100% accuracy and has been published in peer-reviewed academic journals.

“Our classification system has had very good results, over 98%, but we want to keep improving,” said Wasswa, who is collecting more data to capture the exact workflow of Ugandan hospitals. “We need a dataset based on the Ugandan population, which we can hopefully one day compare with classification models from India or China or the US. And by engaging different stakeholders, such as the ministry of health, we can integrate the system across the whole country.”

Kenya: water hyacinth cake

Jack Oyugi’s first job out of university was as a dairy farm manager in Mombasa. As the farm was spending 70% of its expenses on animal feed alone, making a profit was nearly impossible. Oyugi travelled to neighbouring Tanzania and Uganda to source cheaper protein sources such as sunflower and soya to feed his livestock, before realising there was a potential protein at home that he could harvest instead: water hyacinth.

Jack Oyugi, third from right, turns water hyacinth into an animal food supplement. Photograph: James Oatway/Africa prize for engineering innovation

The invasive weed, native to South America, first appeared in Africa in the early 1900s. After spreading from the Cape and clogging up major dams and rivers, it made its way to Lake Victoria, where it has closed off fishing routes and provided a new habitat for disease-carrying mosquitoes. (The plant, dubbed “the world’s worst aquatic weed”, is also the focus of another engineering prize invention: Kenyan finalist Richard Arwa has created a clean cooking ethanol made from invasive water hyacinth.)

Oyugi, who hails from western Kenya, remembers watching livestock graze on the leaves of water hyacinth during droughts. “They’d just graze on the leaves and then move on. But it made me think maybe there was something in it that the animals didn’t like too much, as they didn’t eat the whole plant. That was when I got the idea to process it,” he says.

Harvesting water hyacinth. Photograph: James Oatway/Africa prize for engineering innovation

After taking on a new job as a government researcher in veterinary science, Oyugi, now 28, got funding to experiment with the plant. His first hyacinth cake had about 20% protein – equivalent to sunflower cake, which is sold in Kenyan markets as animal feed – but Oyugi then created a patented fermentation process using a fungus to increase the protein levels to 50%, comparable to soya.

The water hyacinth is steam boiled, dried, crushed and fermented to make a powder, which is then mixed with minerals and energy-rich materials like maize bran to make an affordable feed sold at a fraction of the price of soya feed. In a pilot study, Kenyan farmers experienced a 20% increase in milk production and 30% decrease in feed costs after using Oyugi’s water hyacinth recipe.

Jack Oyugi’s animal food supplement produced encouraging results for Kenyan farmers. Photograph: James Oatway/Africa prize for engineering innovation

Oyugi has received about $50,000 (£38,000) from the Kenyan government to work on the product and, if he wins the engineering prize, plans on rolling the hyacinth feed out to other African countries plagued by the weed, including Ethiopia, Nigeria, Tanzania and Uganda.

“We need to do everything we can to stop our lake from dying,” says Oyugi. “Water hyacinth is here to stay and it is so difficult to get rid of that we need to find a way to work with it. The byproducts from making the feed can be sold as fertilisers and we employ the fishermen as [hyacinth] harvesters, as they can no longer fish because the hyacinth levels are so high.”

Ghana: bamboo bicycles

Cycling enthusiast Bernice Dapaah grew up using her bike to get to and from school on the outskirts of Kumasi in southern Ghana. After graduating from university, she and a few engineering friends decided to take on Ghana’s high unemployment rates by creating jobs in the nation’s burgeoning eco-sector rather than seeking them.

‘It takes only one or two bamboo trees to make one of our bikes’: Bernice Dapaah. Photograph: James Oatway/Africa prize for engineering innovation

Inspired by Dapaah’s childhood, they created a social enterprise focused on making bicycles out of bamboo, which is fast-growing, produces as much as 35% more oxygen than other trees, and helps to prevent soil erosion, a serious issue for Ghanaian farmers. Bamboo bike production is also far less energy intensive than the process for making steel bikes, as the latter emits about 5kg of CO2 per frame.

“Bamboo is abundant in Ghana, and it takes only one or two bamboo trees to make one of our bikes,” says Dapaah.

Bamboo bicycle production keeps energy use to a minimum. Photograph: James Oatway/Africa prize for engineering innovation

“Employment creation and being green are both very important to us. We recycle wheels, gears, brakes and handles [from second-hand steel bikes] and refurbish them, and only a few of the components are imported, like the tyres. The bamboo comprises around 75-80% of our bikes and the epoxy is made from tree fibres; we initially used cassava paste, but it didn’t work. We also plant 10 bamboo trees for every one we harvest for a bike.”

Dapaah’s Ghana Bamboo Bikes Initiative now employs 26 full-time staff, 11 of whom are women, and has sold thousands of bikes – many as far afield as the US and Europe. Her goal is to employ 200 people in her community in southern Ghana, where she has become an activist for bicycle lanes on new roads.

“Cycling is popular in Ghana but the road system is not user-friendly,” she says. “We are pushing to see how the government can integrate bike lanes in the south of the country, because drivers don’t currently care about cyclists and there have been accidents as a result.”

Clement Adade rides one of the bamboo bicycles. Photograph: James Oatway/Africa prize for engineering innovation

Dapaah, who is now working on a bamboo wheelchair design, was named “entrepreneur for the world” at the 2015 World Entrepreneurship Forum and has won a slew of international awards for her bicycle innovation.

EcoRide bicycles currently retail for $200 to $400, and a number of charities have made bulk purchases for Ghanaian schoolchildren.

“People get followed around when they ride a bamboo bike,” says Dapaah. “And a lot of the kids who use bamboo bikes want to study engineering because they want to know how the design works. We want people to ride these bikes because cycling reduces emissions and bamboo is regenerative.”