In the summer of 2016, teenagers Anastasia Georgievskaya and Ivan Novikov were walking along London’s South Bank, picking their way past the food stalls lining the Thames, when they caught an aroma of fried doughnuts that instantly reminded them of childhood.

At dinner that night, the couple started to wonder: If one of them hadn’t been there, would there have been a way to digitally recreate that doughnut smell and transmit it to a distant device—to share in that moment, even if they were miles apart? “At the time, we couldn’t find anything doing it on the market,” explains the now 24-year-old Georgievskaya. “We kept coming back to the idea over the years. Eventually we realized we could do it ourselves.”

Georgievskaya is now CEO of Scentient, a UK startup aiming to integrate smell into virtual reality. Its Escents device sits around the neck and pairs with a VR headset. It carries four cartridges filled with concentrated synthetic scents that mimic smells—smoke, say, or natural gas—that can be released at certain times or in certain locations in the VR environment through a specialized app. Novikov joined as full-time CTO last year, and the first working prototype was completed in November 2022.

Aware of the long history of failed scent-based media products—from 4D cinemas to Smell-o-Vision—Scentient is looking beyond consumer electronics. To begin with, the company’s main focus is on training emergency service workers.

Firefighters, paramedics, and other emergency responders already use a wide array of digital simulations to train for real-world disasters that are expensive or impossible to physically mimic, and adding smell into those training simulations could change the way people behave in their virtual environment. Smells can be used as unique indicators of threats—think the smell of invisible natural gas for firefighters—as a distraction, and even just to help acclimatize workers to the often foul odors they’ll encounter.

The brain’s olfactory cortex, which processes smell, is a direct neighbor to the amygdala, which helps govern our most basic emotional and hormonal responses, and the two regions are heavily interconnected. “That means a smell really helps trigger a fight-or-flight response,” says Georgievskaya. “That basic feeling when you smell something bad, you start looking for a source—or start trying to get away from it.”

Georgievskaya also points to the well-established link between smells and memory. One 2013 study found that olfactory stimuli (the smell inside of a bakery) led to greater brain activity than visual stimuli (seeing a loaf of bread). Smell could therefore be key to pushing through the “uncanny valley” of virtual reality into a truly immersive environment.

Scentient is about to conduct a trial of its device with Hertfordshire Fire and Rescue Service, and going forward the duo have ambitious plans for the company. They rattle off potential use cases, from interactive art exhibits to helping diagnose conditions that affect the sense of smell, such as Parkinson’s. An at-home version for consumers is a lower priority, says Novikov: Flagging sales and high costs mean that the “market isn’t quite ready.”

There are more conventional uses, too. “If you look at virtual reality experience hubs where a group of friends go to, say, play an immersive zombie-shooter, that’s a much more attractive market for us,” Novikov says. “There’s actually been some research on this where people added scent to a VR version of a group horror game and they found that the stress levels and the immersion were much higher.”

But doing all that requires capital. Until now the group has been supported by government startup support agency Innovate UK—the idea won its national Young Innovator Award in 2022—and has spinout support from University College London, Novikov’s alma mater. Scentient recently launched a new funding round, aiming to raise £250,000 (around $317,800) to help get its technology ready for mass production.

“Smell is one of the three senses that really allows you to take in the environment around you,” Novikov says. “If you have a virtual environment with a campfire and you have the crackling sound, and you can see all around you, it’s the additional scent that really makes you feel like you’re there and not smelling your living room.”

This article first appeared in the September/October 2023 edition of WIRED UK.