Wireless Olfactory Feedback System Enhances VR Experiences

Summary: Researchers developed a novel, wireless, skin-interfaced olfactory feedback system capable of releasing various odors. This technology integrates scents into virtual reality (VR) and augmented reality (AR) to provide a more immersive user experience.

The miniaturized odor generators can be attached directly to the skin or incorporated into a flexible facemask, creating a myriad of odor combinations.

This innovation holds significant potential in diverse fields, from 4D movie watching and online education to medical treatment.

Key Facts:

  1. The newly invented system is wireless and programmable, supporting long-term usage without frequent maintenance.
  2. The odor generators operate through subtle heating and mechanical thermal actuation of odorous paraffin wax, creating adjustable odor concentrations.
  3. The technology can create around 30 different scents, with test participants recognizing these scents with a 93% success rate.

Source: City University of Hong Kong

A research team co-led by researchers from City University of Hong Kong (CityU) recently invented a novel, wireless, skin-interfaced olfactory feedback system that can release various odors with miniaturised odor generators (OGs).

The new technology integrates odors into virtual reality (VR)/augmented reality (AR) to provide a more immersive experience, with broad applications ranging from 4D movie watching and medical treatment to online teaching.

“Recent human machine interfaces highlight the importance of human sensation feedback, including vision, audio and haptics, associated with wide applications in entertainment, medical treatment and VR/AR. Olfaction also plays a significant role in human perceptual experiences,” said Dr Yu Xinge, Associate Professor in the Department of Biomedical Engineering at CityU, who co-led the study.

This shows a woman in VR surrounded by roses.
In their experiments, demonstrations in 4D movie watching, medical treatment, human emotion control and VR/AR experience in online teaching exhibited the great potential of the new olfaction interfaces in various applications. Credit: Neuroscience News

“However, the current olfaction-generating technologies are associated mainly with big instruments to generate odors in a closed area or room, or an in-built bulky VR set.”

In view of this, Dr Yu and his collaborators from Beihang University developed a new-generation, wearable, olfaction feedback system with wireless, programmable capabilities based on arrays of flexible and miniaturized odor generators. 

They created two designs to release odors on demand through the new olfaction feedback devices, which are made of soft, miniaturized, lightweight substrates. The first one is a small, skin-integrated, patch-like device comprising two OGs, which can be directly mounted on the human upper lip.

With an extremely short distance between the OGs and the user’s nose, it can provide an ultra-fast olfaction response. Another design is a flexible facemask design with nine OGs of different odor types, which can provide hundreds of odor combinations.

The magic of odor generators is based on a subtle heating platform and a mechanical thermal actuator. By heating and melting odorous paraffin wax on OGs to cause phase change, different odors of adjustable concentration are released. To stop the odor, the odor generators can cool down the temperature of the wax by controlling the motion of the thermal actuator.

By using different paraffin waxes, the research team was able to make about 30 different scents in total, from herbal rosemary and fruity pineapple to sweet baked pancakes. Even less-than-pleasant scents, like stinky durian, can be created. The 11 volunteers were able to recognize the scents generated by the OGs with an average success rate of 93 percent.

The new system supports long-term utilization without frequent replacement and maintenance, and enables interaction with users for various applications. Most importantly, the olfactory interface can support wireless and programmable operation, and can interact with users in various applications. It can respond rapidly to burst or suppress odors and for accurate odor concentration control. And the odor sources are easily accessible and biocompatible.

In their experiments, demonstrations in 4D movie watching, medical treatment, human emotion control and VR/AR experience in online teaching exhibited the great potential of the new olfaction interfaces in various applications. 

For instance, the new wireless olfaction system can interact between the user and a virtual subject when the user is “walking” in a virtual garden by releasing various fruit fragrances. The new technology also showed potential for helping amnesic patients recall lost memories, as odor perception is modulated by experience, leading to the recall of emotional memories.

“The new olfaction systems provide a new alternative option for users to realize the olfaction display in a virtual environment. The fast response rate in releasing odors, the high odor generator integration density, and two wearable designs ensure great potential for olfaction interfaces in various applications, ranging from entertainment and education to healthcare and human machine interfaces,” said Dr Yu. 

In the next step, he and his research team will focus on developing a next-generation olfaction system with a shorter response time, smaller size, and higher integration density for VR, AR and mixed reality (MR) applications.

The findings were published in the scientific journal Nature Communications under the title “Soft, Miniaturized, Wireless Olfactory Interface for Virtual Reality”.

The corresponding authors are Dr Yu and Dr Li Yuhang from the Institute of Solid Mechanics at Beihang University. The first co-authors are Dr Liu Yiming, a postdoc on Dr Yu’s research team, Mr Yiu Chunki and Mr Wooyoung Park, PhD students supervised by Dr Yu, and Dr Zhao Zhao, a postdoc on Dr Li’s research team.

Funding: The research was supported mainly by the National Natural Science Foundation of China, CityU, and the Research Grants Council of the HKSAR.

About this virtual reality and neurotech research news

Author: P.K. Lee
Source: City University of Hong Kong
Contact: P.K. Lee – City University of Hong Kong
Image: The image is credited to Neuroscience News

Original Research: Open access.
Soft, miniaturized, wireless olfactory interface for virtual reality” by Yu Xinge et al. Nature Communications


Soft, miniaturized, wireless olfactory interface for virtual reality

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

Here, we report a concept of skin-interfaced olfactory feedback systems with wirelessly, programmable capabilities based on arrays of flexible and miniaturized odor generators (OGs) for olfactory VR applications.

By optimizing the materials selection, design layout, and power management, the OGs 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.

Representative demonstrations in 4D movie watching, smell message delivery, medical treatment, human emotion control and VR/AR based online teaching prove the great potential of the soft olfaction interface in various practical applications, including entertainment, education, human machine interfaces and so on.

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