The science behind sight, taste, touch, and sound are lightyears beyond smell. Most cameras work better than human eyes, able to see spectrums of light invisible to us. Audio systems can hear wavelengths our ears can’t. Robots can now use an artificial sense of touch to carefully peel a grape. Some artificial flavorings are tastier than the real thing. Similar efforts to capture olfactory sensory experiences have fallen short because the physics behind how our brains smell isn’t as straightforward as other senses. Sight is photons, sound is compressed air. Scent is something else entirely. Roughly 400 receptor types can recognize millions of scents, combining them to create an overall smell.

— Read more in Digital Olfaction Brings Scent Systems Into the 21st Century at Propmodo.