These Wearable "Odor Generators" Add Wire-Free Smell-O-Vision to Virtual, Augmented Reality

Researchers from the City University of Hong Kong, Beihang University, Shandong University, the Hong Kong Center for Cerebra-Cardiovascular Health Engineering, and the China Special Equipment Inspection and Research Institute have come up with a wireless wearable designed to bring Smell-O-Vision to life — adding scents to virtual and augmented reality to enhance user immersion.

"Recent advances in virtual reality (VR) technologies accelerate the creation of a flawless 3D virtual world to provide [a] frontier social platform for human[s]," the researchers explain of the background to their work. "Equally important to traditional visual, auditory and tactile sensations, olfaction exerts both physiological and psychological influences on humans."

That's where the team's creation comes in. While adding programmable scent-dispensing devices to virtual reality systems has been done before, it typically requires the user to be tethered to a series of tubes connected to scent chambers and air pumps. The researcher's vision for virtual smell systems, though, is something more portable — a miniature version, which can be worn by the user and requires no tethers at all.

"By optimizing the materials selection, design layout, and power management, the OGs [Odor Generators] exhibit outstanding device performance in various aspects, from response rate, to odor concentration control, to long-term continuous operation, to high mechanical/electrical stability and to low power consumption," the team claims of its creation. "The miniaturized feature of the OGs enables to form a large array of OGs with different flavors, where the smell type of the OGs can be distinguished by their frame colors."

The team's prototypes take the form of a two-generator and a nine-generator system, one designed to be stuck to the user's skin directly under the nose and the other to be integrated into a face mask. The more generators, the more individual odors, locked in paraffin wax discs until needed, are available for mixing — and, thus, the more complex the olfactory palette presented to the wearer.

To prove their devices' capabilities, the team set about using them in a range of applications — from "4D movie watching," where the viewer can smell what's happening on-screen, to educational projects where a botany teacher can allow a virtual class to smell particular plants. The team even proposed the use of "smell messages" for communication with the deaf and blind, and emotion control through the presentation of different smells.

The team's work has been published under open-access terms in the journal Nature Communications. If you're eager for something you can build yourself, though, the open source Raspberry Pi-powered Nosewise is more readily accessible — and integrates directly with the HTC Vive VR hand controllers.