Comment interesting but (Score 1) 25
This is interesting but it is only half-true that the use of consumable chemicals has been the barrier to the creation of scent emitters. The other problem is that no orthogonal basis for olfaction is known. In the case of color, for example, we know that you can combine red, blue, and green to form any desired color. There is nothing comparable for scent. We don't know that you can use, say, rose, bitter almond, and sandalwood to create any desired scent.