December 3, 2023

While we’ve seen several attempts to generate real-world scents in VR environments, many have involved rather bulky wearables. Chinese scientists have developed a more streamlined system that works on the skin under the user’s nose.

The basic version of the experimental setup consists of two small devices called odor generators (OGs). They are all mounted on a piece of lightweight, flexible base material that temporarily adheres to the skin above the user’s upper lip.

Each OG contains a different scented paraffin, as well as a thermal actuator. When activated wirelessly by the included VR system, actuators in one or both of the OGs heat the wax and cause it to (slightly) melt, releasing its scent. When the actuator is turned off, the wax cools and returns to a solid state where it produces almost no odor.

The relatively simple two-OG version of the system (left) and the more complex 9-OG mask (right)
The relatively simple two-OG version of the system (left) and the more complex 9-OG mask (right)

Liu, Y. et al.

In a more complex version of the system, a total of nine OGs—each with a different scent—are integrated into a flexible mask. These can be activated in hundreds of different combinations and ratios, creating a wide variety of scents.

So far, scientists have created about 30 different scents, including rosemary, pineapple, freshly baked pancakes and stinky durian. In lab tests, 11 volunteers accurately identified the scents produced by the system, with an average success rate of 93 percent.

“The new olfactory system provides a new alternative for users to realize olfactory displays in virtual environments,” said Dr Yu Xinge of City University of Hong Kong, who led the study together with Dr Yuhang Li from Beihang University. “The fast response speed of released odors, high odor generator integration density, and two wearable designs ensure the great potential of olfactory interfaces in various applications, ranging from entertainment and education to healthcare and human-machine interfaces.”

A paper on the research was recently published in the journal natural communication.

source: City University of Hong Kong