Compressed Natural Gas (CNG) has one major benefit over traditional gasoline – it's cheap. About 1/3 of the cost, to be exact. Unfortunately, it also has to be kept under very high pressure, which means that traditional gas tanks simply can't stand up to it. Until now, the only way to store CNG fuel has been in reinforced plain geometric cylinders. Used for their strength, they also take up valuable space and weigh quite a lot. Chrysler is trying to find a better way, using human lungs as inspiration. Enrico Pisino, Chrysler's senior manager of innovation, explains that human lungs store oxygen in numerous small sacs called alveoli, and that his researchers are using this method to design new, stronger storage tanks.