This phase-change mug prototype's mission is to keep your coffee at a perfectly drinkable temperature. It will also stay that way for hours.

"Our goal was to create a coffee mug that will take piping hot coffee and cool it to a hot, but drinkable, temperature—and keep it at that temperature for a long time," Logan Maxwell, the co-creator of the aptly named Temperfect mug, told R&D Mag.

The Temperfect uses a three wall design - an inner wall that holds the liquid, an outer wall you hold and a middle wall that separates them. There's an insulating vacuum in between the outer and middle walls.

Maxwell used a proprietary nontoxic phase-changing chemical that is solid at room temperature but will melt into a liquid when heated by the coffee. That secret sauce is what keeps it at the perfect drinkable temperature.

The Temperfect mug is currently on Kickstarter (and has already broken its $23,500 goal with 20 days to go) [Kickstarter via R&D Mag]