It was when he found a long scratch on the cover of his white MacBook that Min Kyu-choi discovered the problem. What could he do with the plug, which had caused the damage? At a time when laptops, mobile phones and tablets were becoming progressively thinner, it struck the Korean design student that the humble three-pin British plug had not moved far from its bulky form over the years.
After toying with prototypes and two years in production, the solution to the problem is the Mu, also known as the folding plug, a smartphone charger that claims to have cut the size by 70% and has sold some 40,000 units since it was launched at the beginning of 2012.
To look at it straight on, the Mu is a flat rectangular device with curved edges and is slightly thicker than a smartphone. When two flaps are pulled back from the front, the three pins are revealed. By twisting a pivot on which the live and neutral pins are attached by 90 degrees, the full form of the plug emerges.
The lightbulb moment for Choi came at around the same time as the first MacBook Air was released by Apple. While laptop design had resulted in machines which could fit into an envelope, they were still stuck with a plug which was multiple times the size.
Matthew Judkins, Choi's business partner, says: "The problem was then bloody obvious and you kind of go through a process saying how does one solve it. When you look at the plug, the problem is that you have got three pins and they are in a triangular formation and it is fairly obvious what to do then – you just make them flat and in a line and that gets rid of the bulk issue.".
The pair met when the designer was completing a course iat the Royal College of Art, and Judkins, who had a history in startups, was looking for his next project. By that stage, the idea had taken shape in Choi's mind. "A beautiful sketch is one thing but it is not a business. It was just two dudes with an idea," says Judkins.
At the same time as grappling with the engineering questions of whether it could actually be made, the pair also considered whether they should make a plug that could fit on the end of any cable or make a charger, which could then be sold at a premium price and the design licensed out. They went down the charger route. "We have a business where we make and sell stuff and make a margin and we have a licensing business where we supply the solution for someone else to put with their product," says Judkins.
After two years wrestling with the design and production of the unit in Korea, the Mu – the name, chosen by a fan, derives from the 12th letter in the Greek alphabet which is used as a symbol for many things, including small or "micro" – emerged in February 2012 priced at £25. On the side is a USB port so that smartphones, digital cameras and speakers can be powered by plugging in a cable.
Some 40,000 have now been sold of the original design and plans are in place over the coming months to bring out coloured chargers, a more powerful plug for tablets and travel adaptors for Europe and the US. While the retail range of the plugs is growing, however, it is in effect a showcase for what could prove to be the most lucrative part of the enterprise – licensing out the design.
When they were working on the idea for the plug during the initial stages in 2010, the partners considered not actually making the product but instead simply licensing out the technology to mobile phone giants. "But in order to articulate the product well, we needed to get people to use it," says Judkins.
The ultimate goal would be to have the plug in a box with a phone, he said, so that after the initial interest from a consumer when they get their new phone, they are then surprised to find a foldable plug alongside it. Seeing the slimmed down plug, Judkins says consumers would get an additional 15 seconds of wow factor when they open the packaging. The packaging itself would also be slimmed down for shipping, yielding savings in logistics and carbon emissions.
"The whole time that this has been a sketch to [being] a product, we have thought about the moment that this will be a licensing play for these guys because that is how we make money," he said. Talks are ongoing with smartphone companies at present while the firm behind the Mu expects to be in profit in the last three months of this year. Judkins and Choi each own one third of the venture while investors have another third.
There have been sacrifices along the way. A pure rounded design of the closed plug is interrupted by the earth pin sticking out. An idea to put in a cog mechanism to slide the pin in and out would have proved too expensive. "You are faced with a classic example of having a well engineered idea which has hit a cost point versus the absolute beauty of industrial design," says Judkins.
It is unlikely however that the foldable plug will be seen at the end of cable for a table lamp or on a toaster in the near future. There is no problem there to solve, it seems. "If you are never going to use it, like in the wall, then there is no reason to have a folding plug, only when you are lugging it around," he said.
What makes it different
At the heart of the foldable plug is a pivot system, where the live and the neutral pins can be twisted around so that they are in a line with the earth one. The casing of the plug unit can be enclosed around them, flattening the device. Internal connecting points in the pivot mean the plug can operate when it is opened as normal but also when folded up, enabling international adaptors to be attached. When shut, the Mu is 14mm (0.5in) thick and rounded, while a standard plug is about 45mm according to the creators.
• This article was amended on 22 July 2014. It originally said the name of Mu was chosen by a fan and is the Greek word for small or micro. In fact it derives from the 12th letter in the Greek alphabet which is used as a symbol for small or micro. This has been corrected.
