(CN) — As increasingly complex technologies blur the line between the real and digital worlds, researchers now aim to recreate one core human experience that virtual and augmented reality technologies have yet to adequately mimic: the sense of smell.
Making smell-o-vision a reality, researchers on Tuesday presented a wearable device that interfaces with VR and allows the user to smell anything — from the sweet smells of cake or lavender to the infamously foul odor of durian fruit.
The team of researchers from China and Hong Kong on Tuesday also detailed their new technology in a paper published in the journal Nature Communications. Aside from commercial uses like 4D films, the researchers expect the technology to also have medical and educational purposes, citing the strong link between smell and memory and emotion.
Coupled with other "recent advances in virtual reality (VR) technologies," the researchers write in their paper, science is accelerating towards "the creation of a flawless 3D virtual world."
In an email interview with Courthouse News, Yiming Liu, a researcher with the Department of Biomedical Engineering at City University of Hong Kong and chief author of the paper, outlined the importance of smell in general — and of this new technology in particular.
“As we know, olfaction" — that is, the sense of smell — "is one of the typical five human sensations in the real world," Liu wrote. But while scientists have put "extensive research" into recreating senses of sight, sound and touch within virtual reality, the sense of smell has so far garnered "less attention."
Although there have been attempts as creating such a system before, those technologies were bulky and limited in their scope, according to the study — a far cry from this new technology developed by Liu and his team of researchers.
In this case, according to the study, researchers developed a technique that uses "odor generators" made with paraffin wax which are then hooked up to a programmable heat source. As the source heats up, the wax melts and the desired smells are released.
The device, which users wear close to their nose, can create smells in real time, from apples to caramel to even mojito. The technology also allows for a "grid" of smells to create a layered and multi-smell experience.
To test the device, the research team ran VR simulations of people walking through an orchard or picking up a flower. As people interact more closely with a virtual source of smell — for example, by moving a virtual flower towards their virtual nose — the device heats up further, producing stronger smells.
Past attempts at such technology have relied on atomizers — the same technology used for tools like essential-oil diffusers or medical nebulizers for conditions like asthma — but doing so requires "a bottle for storing the liquid odor sources," Liu said in his email interview. Researchers in this case decided to try out wax instead.
Going forward, Liu says this new technology could be another important element in the creation of a realistic metaverse. He imagines there will be commercial uses for it, whether in 4D films or through other VR experiences like games.
It could have more serious uses too, including for schooling or medicine. As students increasingly rely on remote learning, the technology could be applied for educational purposes, researchers note.
The paper also touches on the potential use of such technology to evoke memories in patients suffering from amnesia. After all, Liu explained in his email, "odors bypass the thalamus," the brain's information center, "and go directly to the olfacotry center of the brain." He added this "may explain why odors [can] trigger memories and emotions."
Philosophers from Plato to Kant have long considered smell to be underappreciated sense. Most humans have experienced the flood of emotion and memory that can come from a particular smell like that of an old family recipe.
Now, researchers not only largely understand the science behind these experiences — they're also getting closer to recreating those experiences in virtual worlds. And soon, this technology could be coming to a VR headset near you.
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