👃 This AI Knows What You’re Smelling

Researchers have developed an artificial intelligence system that can predict how a compound smells by analysing its molecular structure. The AI tool describes specific odours with more precision than humans.

Unlike visual cues or sounds, which take the scenic route through various brain regions, smells go straight from the nose to the brain’s emotional and memory centres. That is why the scent of grandma’s cookies can instantly transport you back to your childhood kitchen.

The team at Osmo, a Google Research spin-off, engineered a neural network that can assign one or more of 55 descriptive terms—like “fishy,” “winey,” or “grassy”—to a given odorant. The AI scrutinised the aroma profiles of roughly 5,000 compounds, along with their chemical structures, to identify correlations. The system found about 250 correlations between specific patterns in a chemical’s structure with a particular smell. Researchers used these findings to create an odour map, which the AI can refer to when predicting the scent of a new molecule.

To validate the system’s scent-detection skills, researchers trained human volunteers to use the same descriptive vocabulary as the AI. When exposed to hundreds of synthetic odorants, the model’s guesses often aligned more closely with the average human response than any individual’s estimate.

Don’t get me wrong; the AI isn’t about to replace your favourite perfumer just yet. The next challenge is understanding how different odorants combine to create new scents. Consider the complexity of predicting the smell produced by mixing 100 molecules in sets of 10—that’s a staggering 17 trillion combinations! Even for a computer, that’s a lot of sniffing around.

Still, the AI’s ability to predict scents based on molecular structures opens up exciting avenues for creating new synthetic aromas. It also offers insights into how our brains process smell, with far-reaching implications in neuroscience and the fragrance industry. As computational power grows and algorithms get smarter, we might crack the code of the olfactory world. 

So, the next time an elusive scent tickles your nostrils, and you can’t quite identify it, remember: an AI might soon be able to tell you exactly what you’re smelling.

Elia Kabanov is a science writer covering the past, present and future of technology (@metkere)

Illustration: Elia Kabanov feat. MidJourney.