A path has opened to taste food in the virtual world before going to a restaurant. Scientists have succeeded in replicating taste in virtual reality (VR). Until now, one could immerse themselves in augmented reality (AR) by combining virtual information with visual and auditory stimuli, but with the addition of taste, it seems that even more diverse experiences can be had in the virtual world.
◇ Gel sprayed with micro pumps provides taste to the tongue
Researchers from Ohio State University and Dalian University of Technology in China revealed on the 1st that they have developed "e-Taste," a human-machine interface (HMI) that allows people to taste food virtually. HMI is a technology that facilitates the consolidation of humans and machines. The research results were published in the international academic journal "Science Advances" on the same day.
Implementing taste in the virtual world has been difficult. While techniques like applying electrodes to the tongue to pass current or altering temperature to mimic taste have emerged, there were limits to replicating taste. The research team stated that e-Taste uses actual flavor components to replicate all five basic tastes, from salty to sour, sweet, bitter, and umami.
e-Taste created taste with chemical substances. Sodium chloride was used for saltiness, citric acid for sourness, glucose for sweetness, magnesium chloride for bitterness, and glutamate for umami. Depending on the taste, these substances were mixed into a gel form and delivered to the tongue through a mini pump attached to the lower teeth.
In tests with 16 individuals, the research team received positive evaluations for the safety, flavor adjustment capabilities, and the ability to reproduce various flavor combinations with e-Taste. In particular, e-Taste provided complex flavors such as chicken soup and lemonade by combining the five taste components.
The potential of e-Taste is limitless. Users can taste food received as rewards in games, and sample flavors before purchasing food items from online shopping malls. It could also help with dieting by providing satisfaction without actually consuming food.
The research team noted, "e-Taste can only replicate tastes that combine five taste components and cannot reproduce the texture or temperature of food" and added, "We plan to incorporate more flavor components in the future and add technology to replicate food's temperature and texture."
◇ Implementing fruit and green tea flavors with lollipop devices
In November last year, researchers from Hong Kong City University unveiled a lollipop-shaped device that provides taste. The device produces flavors when licked like a candy. Sweetness and saltiness were given with sugar and salt, and sourness with citric acid. It could also produce flavors of cherry, passionfruit, green tea, milk, durian, and grapefruit, using substances extracted from the fruits or drinks.
The research team included chemical substances capable of producing nine different tastes in the gel. When current is applied, the chemicals are released from the gel, allowing users to taste them. A stronger current results in more chemicals being released, increasing the flavor intensity, while a weaker current decreases it. The taste delivery device weighs 15 grams, similar to the weight of a real lollipop. The research team stated that the lollipop device operates safely with less than 2V of electricity.
Researchers from Hong Kong City University have also added a device to deliver odor components to implement smells closely related to taste. For example, adding a lemon scent when the user tastes something sour can create the feeling of drinking lemonade.
However, this device has the drawback that the gel must be replaced after one hour of use. The research team noted, "We will extend the gel usage time and diversify the types and intensities of tastes to solve this issue."
References
Science Advances (2025), DOI: https://doi.org/10.1126/sciadv.adr4797
PNAS (2024), DOI: https://doi.org/10.1073/pnas.2412116121