The watchword for designers now is sustainability and all could learn from British inventor Trevor Baylis who in 1991 designed the wind-up radio. Watching a documentary on the spread of HIV/Aids in Africa, he heard public health workers saying radio messages were an effective way to communicate information about the disease but it was hindered by lack of access to batteries in remote areas.

His wind-up radio – the first prototype made in his garage delivered 14 minutes of sound – was credited with bringing life-saving information to millions of people. By 1994 he had refined it sufficiently and an appearance on BBC’s Tomorrow’s World programme led to an investor coming forward to help put it into production. It was manufactured in South Africa and then distributed by aid agencies.

In 2011 he told the Financial Times: “The hard part was convincing people that I was not some sort of wally who was off my trough.” He made little from his invention and, prior to his death in 2018, he was an active campaigner in trying to get more legal protection for inventors.