In a small lab at Ohio State University, a new device could potentially be the next big thing in virtual reality. Researchers call it “e-Taste,” and it does something no VR headset can: let you taste food that isn’t actually there.

For decades, developers of virtual reality (VR) and augmented reality (AR) systems have struggled to engage all five human senses. We’ve had visual immersion through high-definition screens, sound through spatial audio, and even touch through haptic feedback. But taste has remained stubbornly elusive. Until now.

The Missing Virtual Ingredient

The e-Taste device operates on a simple but clever principle: it captures the molecular makeup of food and drinks, transmits that data wirelessly, and recreates the taste on the other end.

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

How does the e-Taste work? First, an “electronic tongue” analyzes food by detecting five key taste molecules—glucose (sweet), citric acid (sour), sodium chloride (salty), magnesium chloride (bitter), and glutamate (umami). Then, using a small electromagnetic pump, the device pushes a precisely mixed liquid through a hydrogel and into a user’s mouth, delivering the corresponding taste.

“Based on the digital instruction, you can also choose to release one or several different tastes simultaneously so that they can form different sensations,” Li explained.

Ok, but does it work?

To test their invention, researchers conducted a series of experiments. A volunteer in California dipped the device’s sensor into a cup of lemonade, while another user in Ohio received the taste profile remotely. The system successfully recreated the drink’s sweet and sour notes, allowing the remote user to experience the taste as if they had sipped it themselves. In another trial, six volunteers tasted combinations designed to mimic lemonade, cake, fried egg, fish soup, and coffee. The results suggest an impressive 86.7% accuracy in distinguishing the intended flavors.

Yet, the system has its obvious limitations. Unlike a real meal, e-Taste cannot replicate texture or temperature. It also struggles with more complex sensations like spiciness or fattiness. “People will get something like a straw in their mouth, and thus placing it to specific locations when needed,” said Yizhen Jia, a co-author of the study.

Beyond Virtual Dining

VR tech like e-Taste could be integrated into immersive VR games, where players taste in-game foods, or used in remote food sampling, allowing customers to “try before they buy” from an online store.

In healthcare, e-Taste could be used to study taste perception and develop personalized nutrition plans. “Sensory loss, particularly gustatory impairments, represents a challenge for individuals with traumatic brain injuries and patients with long-haul COVID,” the researchers of the study note. The device might help improve appetite and nutrition for those who struggle to taste food normally.

“Taste and smell are greatly related to human emotion and memory,” Li said. “So our sensor has to learn to capture, control, and store all that information.” The technology also joins a long history of sensory experimentation in media. Decades ago, theaters tried scent-based movie experiences like “Smell-O-Vision.” However, the concept was dropped due to the lack of accuracy and scalability regarding scent recreation.

Despite its promise, e-Taste is still in its early stages. The researchers acknowledge that their device currently relies on a limited set of chemicals, which may not fully capture the complexity of real-world flavors. Additionally, fine-tuning the timing and concentration of tastants is really important for a more natural taste experience.

And while wearing a lightweight taste-actuation device might appeal to gamers and researchers, it remains to be seen whether the general public would embrace this “digital tongue” in their daily lives.

“This concept is here,” Li said, “and it is a good first step toward becoming a small part of the metaverse.”

The findings appeared in the journal Science Advances.