Sir James Dyson's innovation awards inspire some of the smartest and oddest new inventions

But will any of this year's crop change the world?

Problem solvers wanted: that's the motto of the annual James Dyson Award, given by the designer and his foundation to students whose inventions "solve a problem". That problem can be as small and simple as too-cool toast, and as large and complicated as a severe drought.

This year the competition has had more than 500 entries from the 18 participating countries, and the 2012 UK winner – which will now go forward to the international competition – is the SafetyNet: a device to improve the sustainability of trawler fishing.

A low-maintenance illuminated ring that can be retrofitted to any trawler net, the device prevents holes in the net closing during trawling, and guides younger, smaller fish to the exit, so that only large fish are caught, and the marine ecosystem is left less damaged.

Dan Watson, who designed the SafetyNet, is 26. At school, he expressed an interest in industrial design and was sent by one of his teachers to meet Bruce Brenner, a leading designer at Dyson, who advised him to study mechanical engineering to gain an understanding of technical systems.

Watson took Brenner's advice, and while studying Project Design Engineering in Glasgow, he says, he read an article about Scottish fishermen being arrested in Norway for throwing fish back into the sea. "I was looking for a problem for my final year project, and this was something I could investigate and immerse myself in. I went to fishing communities in Scotland to learn about the problem; I went out on trawlers; I read up on past experiments to see what phenomena might be useful [such as the responses of fish to light]. Fishermen who use sustainable fishing gear are allowed extra days at sea, so the system could pay for itself very quickly.

"The project was aimed at helping fishermen as much as the fish they catch. The idea was to try to find a solution that would work for all the involved parties – the fish included."

After graduating from Glasgow, Watson returned to London and the Royal College of Art's Innovation Design Engineering course. "I worked on a group project to develop a new visual password system, and a solo project looking at how human emotions might be used to communicate levels of risk. SafetyNet was in the background. It's taken me three years so far."

The award, its namesake explains, is intended to both support and inspire young designers. "Students must be inspired to take up the challenge of engineering," says Dyson. "Being put in the spotlight is vital for these fledgling inventors. Their success will spark yet more young bright minds to emerge."

Last year's UK winner saw his business boom after he was awarded the prize. Michael Korn, 31, is the inventor of the KwickScreen: a portable, retractable room divider for hospitals. It's now in use not only across the NHS, but also in Korea, Turkey, Holland, Ireland, Belgium and Canada, and was used in polyclinics for athletes at the Olympics. Korn created the screen after hearing about space problems in hospitals from his sister, a doctor. "It was my intention to invent a product that was simple but solved a big problem, that I could turn into a business," says Korn, who also studied Innovation Design Engineering at the RCA. "The award gave our NHS customers that extra bit of confidence and credibility, so our sales skyrocketed."

Watson's SafetyNet is now set to compete in the £10,000 international award, against designs from 17 other countries (including those above). Judged by an international panel of designers, engineers, academics and journalists, and adjudicated finally by Dyson himself, the winner will be named on 8 November.

Last year's triumphant design was the AirDrop, a device that captures water vapour from the air and feeds it back into the soil in arid farming areas. It was designed by Edward Linacre, from Melbourne.

The £1,000 prize money for the national award, Watson says, will allow him to do more testing on the SafetyNet, while the exposure has attracted others keen to help him with trials before it goes into production.

Though he plans to see his successful invention through to completion, Watson is eager to move on to new projects, too. "One of the reasons I got into design is that the need changes so frequently and massively. There are always so many interesting problems out there to solve."

International contenders

1. Hop (Spain)

Hop says its creator, represents the "next generation of luggage". By following the signal from its owner's smartphone, it can follow its owner through an airport on built-in caterpillar tracks. In the future, it could reduce or remove the need for baggage carts and carousels. Although it might cause a few terror alerts in the meantime.

2. Tostit (France)

The designer of the Tostit saw a series of problems with the traditional toaster. Much of the heat is wasted by moving up and out of the toasting slot; the same amount of energy is used for a single slice as for two slices; the toast doesn't stay hot and crispy for long enough after toasting; and the toaster is tied to the worktop by its troublesome power cable. This is a solution.

3. Baridi (Belgium)

Among the many entries for the Dyson award are a number designed expressly to benefit people in the developing world. In Africa, around 40 per cent of fruit and veg crops fail to reach customers due to poor transport and lack of refrigeration. The Baridi is a small, easily moveable climate-controlled chamber, powered by sunlight, which could dramatically reduce that percentage.

4. AirGo (Malaysia)

The cabin design of commercial planes has remained largely unchanged since the 1960s, but the inventor of the AirGo system (top right) believes he can improve the notoriously cramped space of economy class, providing comfort comparable to first class, without taking up extra floor room.

5. O2 Pursuit (Australia)

The O2 Pursuit is a motorcycle that runs on thin air. It can be used for commuting or dirt biking, and was designed to point the way towards an emissions-free future for transport. For the bike to be mass-produced, of course, there would also have to be an infrastructure of air-refill stations.