A mobile phone charger that can be powered by either a cold beer or a hot coffee has been unveiled.
The Epiphany One Puck, which doubles as a drinks coaster, connects to a phone with a USB cable.
It has two sides, one red, one blue.
Owners use the red side as a drinks coaster to place a hot drink on it, and the blue side as for a cooling drink such as a beer.
It uses something called a Stirling engine to turn heat into energy.
US company Epiphany Labs, based in New Castle, Pennsylvania, has built a working prototype and hopes to have it on the market early in 2014.
The company is still vague on just how long it takes for the device to charge up a phone because there are a lot of variables at play, including how hot or cold the source is.
Any source of heat that can fit on the Puck will work.
It works best with something that's very warm like a steaming cup of tea or coffee or very cold like a well chilled beer or soft drink.
Epiphany is aiming to raise £63,000 on fund raising website Kickstarter to turn the prototype into a gadget that can be mass-manufactured.
By Feb 8, more than £25,000 (pounds) had been raised, and early birds can still get in for a £62 pledge price.
The regular pledge for a Puck will be £73.
Tim Joseph of Epiphany said: 'We called it Puck because of its shape.
'We added "onE" Puck not only to imply that it is the one solution to this problem, but also to go with our ongoing theme that Epiphany has onE vision for onE world that we all share.
'The onE Puck is a neat gizmo for cell phone users, but the implications of this project are much farther reaching than just cell phones.
'Once we have this project off the ground, we'll get to work on larger scale versions of the onE Puck that will provide inexpensive power to households and villages using nothing but waste heat as the energy input.
'There's nothing new about the idea of using Stirling engines to do that, but no one has ever successfully brought them to market in an affordable package.'