This Device Can Synthesize Any Flavor on Your Tongue: Taste the Rainbow

Back in the 1990s a team of engineers created a device called the iSmell. This unusual gadget used scent cartridges to simulate a wide variety of aromas, which could be triggered through computer code. The iSmell ultimately failed due to lack of market interest, but I always thought the idea that you could create anything from the smell of hot chocolate to pepperoni pizza just by mixing chemicals was pretty fascinating.