Experience flavour without food: A new device makes it possible

A groundbreaking technology is set to transform the virtual reality experience by introducing a new sensory dimension: taste.

The innovative 'e-Taste' interface utilizes sensors and wireless chemical dispensers to enable remote taste perception, also known as gustation. Researchers at Ohio State University conducted field tests, confirming the device’s ability to digitally replicate a range of taste intensities while ensuring both variety and user safety.

Designed to detect glucose and glutamate molecules, the sensors interpret the five fundamental tastes—sweet, sour, salty, bitter, and umami. The collected data is then converted into electrical signals and wirelessly transmitted to a remote device for accurate taste simulation.

"The chemical dimension in the current VR and AR realm is relatively underrepresented, especially when we talk about olfaction and gustation," said Jinghua Li, co-author of the study and an assistant professor of materials science and engineering at Ohio State. "It's a gap that needs to be filled and we've developed that with this next-generation system."

Inspired by Li's previous biosensor research, the system features an actuator composed of two key components: a mouth interface and a compact electromagnetic pump. This pump is connected to a liquid channel containing chemical solutions, which vibrate when an electric charge is applied, pushing the solution through a specialized gel layer into the user's mouth.

According to Li, the duration of the solution’s interaction with the gel layer determines the intensity and strength of the perceived taste, allowing for precise adjustments.

"Based on the digital instruction, you can also choose to release one or several different tastes simultaneously so that they can form different sensations," she said.

Taste is a subjective sense that can change from one moment to another. Yet this complex feeling is the product of two of the body's chemical sensing systems working in tandem to ensure what you eat is safe and nutritious, the gustation and the olfactory (or smell) senses.

"Taste and smell are greatly related to human emotion and memory," said Li. "So our sensor has to learn to capture, control and store all that information."

Despite the difficulty involved in replicating similar taste sensations for a majority of people, researchers found that in human trials, participants could distinguish between different sour intensities in the liquids generated by the system with an accuracy rate of about 70%.

Further tests assessing e-Taste's ability to immerse players in a virtual food experience also analyzed its long-range capabilities, showing that remote tasting could be initiated in Ohio from as far away as California. Another experiment involved subjects trying to identify five food options they perceived, whether it was lemonade, cake, fried egg, fish soup or coffee.

While these results open up opportunities to pioneer new VR experiences, this team's findings are especially significant because they could potentially provide scientists with a more intimate understanding of how the brain processes sensory signals from the mouth, said Li.

Plans to enhance the technology revolve around further miniaturizing the system and improving the system's compatibility with different chemical compounds in food that produce taste sensations. Beyond helping to build a better and more dynamic gaming experience, the study notes that the work could be useful in promoting accessibility and inclusivity in virtual spaces for individuals with disabilities, like those with traumatic brain injuries or Long Covid, which brought gustatory loss to mainstream attention.

"This will help people connect in virtual spaces in never-before-seen ways," said Li. "This concept is here and it is a good first step to becoming a small part of the metaverse."

Other Ohio State co-authors include Shulin Chen, Yizhen Jia, Tzu-Li Liu, Qi Wang and Prasad Nithianandam and Chunyu Yang, including Bowen Duan and Zhaoqian Xie from Dalian University of Technology, Xiao Xiao and Changsheng Wu from the National University of Singapore, Xi Tian from Tsinghua University. (ANI)