This might actually bend the definition of "refrigerator" a bit, but it's still a neat idea: Industrial designer Yuriy Dmitriev submitted the above concept for a zero-energy fridge to the Electrolux Design Lab competition, where it won a semifinalist spot. Dmitriev's design consists of a pool of green, luminescent polymer gel not unlike Nickelodeon Gak™ (though to the best of our knowledge, it is not, in fact, made of Nickelodeon Gak™), into which you can press foodstuffs to store them in a gel that preserves them from decay. In theory, pressing the food into the Bio Robot Refrigerator creates a separate storage capsule for each item.