Exploring new ways to generate smell for wearable devices
Current commercial technology used to produce artificial scents is inefficient. It requires large machines and can only work for one room at a time, this means each room can only have one scent, and changing scents requires the room to be completely ventilated and the air changed. This is a lengthy and inefficient process.
Despite the challenges of size and localisation, touch and smell remain important senses to explore in virtual reality technology.
Dr Yu Xinge from the Department of Biomedical Engineering of City University of Hong Kong his colleagues have developed a new smell generating system that is portable, wireless, and real-time.
The creation of the generators
The artificial smells are generated by a heating element and paraffin wax. The odours are released at the temperature of phase change. Activation to phase change takes 1.44 seconds. The team made two versions of wearable devices. One version sits between the nose and upper lip, and the other is a face mask. Both devices carry the same odour generators. Due to its size, the nose version carries two generators, offering two scent options at a time. But with a three-by-three layout of nine generators, the mask version of the device is able to generate hundreds of different smells. This can be achieved by programming different run times for each generator, variable combinations of activated generators and the temperatures of the heating elements.
Reality-changer
The first application the team put the new devices to is immersive movie watching and virtual reality. Virtual reality (VR) is an ever-growing space in technological development, with many applications, such as gaming, theme park rides and recently, the metaverse. In order to bring VR closer to reality, developers have mainly used vision and sound to mimic an environment for the user. The most common device for VR is the headset. These display an image inside the headset, giving immersive visuals.
There are developed wearable smell generation systems available, however these are often wired, heavy and creates a less than desirable result.
In film viewing and in VR, as the subject moves closer to a source of a smell, the dimension of smell can be added by gradually increasing the temperature of the heating elements, and decreasing as the subject moves away. These generators are shown to be able to work independently.
Talking with smell
Humans communicate mainly with the senses vision, speech, hearing, and touch. This includes talking, sign language, reading, braille. However, visual and speech impaired individuals are often limited to only using touch. Yu expressed that braille is not very efficient and accessible at all times, and is easy for readers to make errors.
Another use for this device the team pieced together is to convey messages with smells generated by the devices. Think of it as sign language but with smells. The team trained users to associate different smells to certain events, people, activity or location, and upon release of the smells, the team found that users are able to remember smells and interpret them according to the training. As the device has wireless capabilities, it will not limit the user to a fixed location while using the device.
Smelling happy
Humans react differently to various smells, think walking past a restaurant, think the smell that triggers a memory. Aromatherapy involves the use of essential oils to promote physical and emotional well-being. Studies have shown that certain scents, such as lavender, can help to reduce anxiety and improve sleep quality. The research team looked at this nature of humans and put together the idea to alter emotions through scents generated by the device.
Novel Creative Solutions
With the capabilities of this new technology, there are no short of new ideas for its applications. Yu agrees that new approaches in using this technology are underway. In a preliminary test, the device was used for treating nerve damage related to smelling. He adds: “Our preliminary results show we can use our device to train people to recover these smell sensations much faster.” Alternatively, another example of this could be the use of smell to promote healthier eating, by adding extra scent to healthy yet sometimes under-seasoned food, individuals may enjoy a better eating experience. Dr Yu and his team published their research in the journal Nature Communications.