A New Device Lets You Taste Things without Actually Eating Them

By Gayoung Lee edited by Andrea Thompson

Imagine you’re virtually walking through a forest during the Mesozoic era, when dinosaurs roamed Earth. As you pass some shrubs, you notice strange-looking fruit with a label that reads, “Taste a Stegosaurus’s Favorite Food!” So you reach into your pocket, grab a small cube attached to a thin plastic strip and hold the strip between your teeth. Immediately, your tongue is filled with a sweet-and-sour tang.

This kind of experience might be realized in the not-too-distant future, according to a new study published on Friday in Science Advances. Immersive technologies such as virtual or augmented reality already do a pretty good job of reconstructing visual and auditory elements of experiences that can transcend space and time. But the developers of “e-Taste”—a tiny cube, measuring about 15 millimeters (0.6 inch) on each side, that is filled with electric sensors—wanted to add taste to the available repertoire of virtual senses.

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For users, the way e-Taste works is simple. You hold the strip in your mouth, with the cube dangling outside. When the sensors inside the cube detects a food object (for example, the “Stegosaurus’s Favorite Food”) in the virtual environment, e-Taste releases a combination of chemicals that simulate five different tastes—salty, sour, sweet, bitter and umami—replicating the experience of taste without requiring you to actually eat anything. Inside, the cube has small, refillable packs of liquid chemicals that are combined in different amounts to produce specific tastes. In the case of the imaginary fruit, for example, glucose and citric acid would be used.

The role of taste in virtual realities has been relatively underexplored because “taste is not just taste—it comes with other stuff like smell and texture,” says study co-author Yizhen Jia, an engineer at the Ohio State University. To be clear, e-Taste can’t yet replicate smell or texture, although Jia and his colleagues have already started exploring ways to include those elements. “We do have a more [improved] design that’s currently in progress,” Jia says, “and then also another work that’s trying to address smell.” But they researchers are confident that they are off to a good start, he adds, because e-Taste demonstrates it is possible to imitate tasting experiences in a “compact, flexible way without a very bulky, large device.”

Even as it is now, however, e-Taste represents a significant advance in biomimetics, or the field in which researchers create artificial copies of natural systems to solve human problems, says Tae-il Kim, a bioengineer at Sungkyunkwan University in South Korea, who was not involved in the new study. One important objective of bioengineering is to develop technologies that work seamlessly with our bodies, as if they were a “part of us,” Kim explains. For instance, certain concepts behind e-Taste, such as emulating our tongue’s sensory functions and quantifying taste in chemical terms, could have extensive medical applications—such as wearable devices that people could use to make daily checks for health-related abnormalities. Such a device could perhaps stimulate different parts of the tongue to, say, determine if the brain was processing sensory signals properly.

Certainly, all this is still speculation, Kim says, but it does demonstrate the kind of advances bioengineers have been able to make in recent years. “The end goal for [bioengineers] is not just to stop at making exact replicas of nature but also to understand why something works the way it does,” he says. “That’s how we make technology that people not only want but also actually need—for example, by improving accessibility. It’s all part of that long-time quest.”