Virtual Taste

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Virtual taste. The idea sounds otherworldly; like something out of a kitschy sci-fi novel. By pairing electrical currents with specific scents, colors, and temperatures, University of Maine engineer, Nimesha Ranasinghe, has discovered how to actually simulate flavor. Ranasinghe believes that, one day, his technology could disentangle flavor from nourishment and inspire new, digital-physical hybrid culinary experiences. His virtual snacks thus far include a lollipop, a cocktail, and a glass of lemonade. “I think the problem is that we [sometimes] eat and drink not because our bodies require it, but to satisfy ourselves, or our cravings. If you can use this type of technology just to satisfy our cravings, and we eat only to nourish our bodies, I think that would be a great device,” Ranasinghe explains. 

So often, the new technologies we encounter seem redundant. We’ve heard it all before—optimization, AI, personalization—just marketed with slightly variant fonts. But sometimes, an engineer will propose something so strange it seems improbable, possibly alien. Yet when described in detail, the idea begins to feel almost prima facie obvious, even inevitable. After all, a computer appears to be a mystery box until you understand the machine as carefully interwoven circuits. In the same vein, Ranasinghe would have us believe that virtual taste is just a set of hacks and workarounds of our pre-existing biological circuitry, and a more reasonable and worthwhile invention than we might first think. 

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Ranasinghe’s primary medium is electricity. Unlike hearing or seeing, our sense of taste is a result of chemical interactions which affect the taste buds that line the inside of our mouths. These pink bulbs are packed with receptor cells that process the chemicals in our food and communicate corresponding sensations of sweet, sour, bitter, salty, and umami (the savory taste associated with glutamates) to our nervous system. But electric currents can exploit the naturally existing ion channels that our taste receptors use to distinguish between flavors.  

“When you change the frequency and the magnitude of current, people perceive them as different sensations,” Ranasinghe says (the method was partially inspired by electrogustometry, a rarely-used method of measuring taste by passing controlled electric currents through a patient’s tongue). How the electricity makes it to the tongue depends on what, and how, you’re eating. One of Ranasinghe’s first inventions, a chopstick and bowl set, manipulates electric currents to make mashed potatoes and miso soup taste salty and sour. The electric current is transmitted to the tongue through highly-conductive silver electrodes, which line the chopsticks and the rim of the bowl. He also incorporated a similar delivery method in a spoon.

Virtual reality headsets don’t alter our vision, but rather, they change what we see. Similarly, virtual taste doesn’t change how we perceive flavor itself, but simply alters what we’re tasting; it makes it more technologically adaptable. But flavor is broader than just taste. The scent of a meal wafts through our nasal passages, and we feel the texture and consistency of food inside our mouths. Temperature, too, influences how we feel about what we’re eating. 

So much of Ranasinghe’s work has relied on this kind of synesthesia—finding workarounds toward creating a virtual experience that in some way simulates real flavor. One strategy is rapid temperature change. Heating, Ranasinghe found, can simulate spiciness, while cooling is reminiscent of a mint or menthol-like sensation. “Interestingly, we also found out that when you heat up and cool down rapidly, people perceive minor sweetness on the tongue,” he explained. His other inventions incorporate scent and colors as well, which all create the illusion of flavor. Even virtual vision can augment the experience of eating. At the University of Tokyo, researchers have used virtual reality goggles to change how a cookie tastes to a user. The researchers also found that by manipulating the apparent size of food, we can augment feelings of satiety.

What’s innovative about Ranasinghe’s approach to virtual taste is that it doesn’t rely on the physical delivery of chemicals. That was how two other efforts -- British scientists developing a virtual reality helmet and “TasteScreen” creator Dan Maynes Aminzade -- believed it could be done. But Ranasinghe says the work is about finding sensations that will contribute to the realism of the experience. He adds that his work represents an early step toward what virtual taste could be. “It’s kind of like television in the 1960s, like black-and-white. You can see the picture, but there are many avenues you can explore,” he said. 

Of course, these nascent technologies have their limitations. Ranasinghe’s electric current flavor only exists while your tongue is in continuous contact with the electrodes, so potatoes eaten with a salty electric current only taste salty when the chopsticks are actually in your mouth. Another challenge is neatly hiding the electronics in his devices, which Ranasinghe says is necessary because “it’s not obvious to have electronics in your food.” Unsurprisingly, he says his products sometimes produce a metallic taste.

But artificial representations, Ranasinghe’s included, have never been perfect. Audio recordings are not live concerts; photographs of the Mona Lisa aren’t the actual painting. Still, for convenience, we’re willing to sacrifice a bit of realism. In fact, it’s comforting that the physical world (if that’s still a distinct category) is not perfectly imitable. 

Jean Baudrillard called the hyperreal “the generation by models of a real without origin or reality.” This appears to be what Ranasinghe ultimately aspires to—a type of taste experience that overlays the physical with the virtual to create a unique flavor experience that doesn’t exclusively belong to either domain. Even the most practical applications that Ranasinghe anticipates from his work combine the two. For instance, his current research is oriented toward helping the elderly, who might be experiencing declining taste capabilities, to better enjoy the food they’re eating. People with other dietary limitations could also benefit from the technology.

His more far-out creations go further. “Imagine you are walking into a bar, and you want to do some experiments, or you want to alter the [imposed] flavors while keeping the real flavor as it is,” Ranasinghe explains. “Using this method, everything happens completely external to the beverage.” While working on his “Vocktail,” a virtual cocktail, Ranasinghe added scent cartridges and color to impose the taste of alcoholic beverages onto a cup of plain water. Air pumps inside a 3D-printed glass emit scents, such as lemon and mint, to the water’s surface, while colored LEDs make the water create the illusion of a flavored cocktail. Meanwhile, a small silver mouthpiece delivers the sensation of the electric current to the drinker’s mouth. Ranasinghe envisions diners using his technology to manipulate the flavors of a margarita or mojito. Imagine an aperitif that transitions from sour to salty as you drink it, or soup that fluctuates between spicy and minty as you slurp.  

Ramasinghe also wants virtual taste to have a social component. “In the real world situation, we share beverages, and we can eat something together. We don’t have any media or technologies to simulate those experiences in a remote situation,” he explained. “You’ll never be able to share a taste or a flavor.” For a potential solution, the computer scientist developed a way to “send” lemonade to others. He uses a sensor to capture the pH and color of lemonade, and then recreates the same drink in another tumbler full of water, using LED lights and sour-tasting electrical currents. Ranasinghe says it’s similar to capturing a photo and sending it to a loved one. Imagine the taste of your dinner, sent along Facebook Messenger just like a GIF. 

With virtual taste, we wouldn’t just have a way to taste something from nothing. Ranasinghe’s technology -- or at least, its premise -- offers new ways to augment everything we already eat, only with virtual additions, like his electric currents, working alongside our seasoning and core ingredients.

In that sense, incorporating a virtual dimension into our food wouldn’t be inherently good or bad. Like all cooking instructions, its inclusion would simply provide another opportunity to perfect -- or profoundly destroy -- our favorite meals.

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.

Dr. Nimesha Ranasinghe, MIM lab, University of Maine.