Experiencing food in VR games? This sensor will provide a genuine taste sensation.

      In recent years, researchers have been exploring ways to enhance virtual reality (VR) experiences to be more immersive and personalized. For instance, in 2022, experts at Stockholm University developed a device called an olfactometer, which allows users to smell scents related to what they're viewing in a VR game while wearing a headset.

      However, smell is just part of the experience. What if it were possible to actually transmit a real taste to someone’s tongue? A team from Ohio State University has introduced a sensing system known as e-Taste that can replicate the flavors of actual food and beverages, delivering them directly to the tongue of another person located hundreds of miles away.

      The e-Taste system comprises two main parts: a taster and a receiver. The taster includes a specialized patch capable of detecting the key molecules associated with the five basic tastes: bitter, salty, sour, sweet, and umami. In their research, the team concentrated on identifying glucose and glutamate on the sensor patch.

      How does it work?

      During trials, a participant in California sampling lemonade dipped the taster patch into the drink. The sensor patch measured the concentration of target chemicals in the lemonade and sent that electrochemical data to a receiver kit located in an Ohio lab.

      The receiver part consists of a patch that rests on the tongue and a pump connected to a liquid channel of solutions. When stimulated electrically, the fluid travels through a gel-based system onto the person's tongue, providing a realistic taste sensation. The specific taste and its intensity can be modified by adjusting the fluid volume released by the pump. In human trials, participants wearing the receiver kit achieved about 70% accuracy in identifying varying levels of sourness.

      “Beyond enhancing gaming experiences, the research suggests that this work could also aid in improving accessibility and inclusivity in virtual environments for individuals with disabilities, such as those with traumatic brain injuries or Long Covid, which has brought attention to taste loss,” the team noted.

      It might also assist in identifying and tasting potential food sources in challenging conditions, facilitate online shopping, support remote education, ensure quality monitoring for freshness and consistency through robotic machines, and allow doctors to analyze taste perception remotely.

      The team tested e-Taste across two types of network protocols. The short-range implementation covered 200 meters, while the long-range version relied on an internet connection without distance limitations.

      Possibilities for VR and beyond

      “This concept is a promising first step towards becoming a small part of the metaverse,” stated Jinghua Li, co-author of the paper and faculty member at the university.

      This is not the first effort to enhance the VR experience with the senses of smell or taste. Two years earlier, OVR unveiled the ION 3 wearable kit for XR hardware capable of generating hundreds of scents using a cartridge system. Additionally, researchers at City University of Hong Kong and Beihang University in China developed a patch-based wearable sensor that utilizes miniaturized odor generators with perfumed wax.

      The VR kit can recognize visual stimuli and produce the corresponding scent in about two seconds. However, when it comes to taste perception, smell (or olfaction) plays an equally significant role.

      The industry has already developed methods for incorporating smell into AR and VR experiences. The e-Taste system illustrates that it is also feasible to remotely evoke realistic taste sensations on the tongue.

      In addition to lemonade, the team also tested volunteers with food-grade chemicals that simulate the flavors of cake, fried eggs, coffee, and fish soup. This mixed-taste analysis was conducted using a combined channel e-Taste system known as the digital cup.

      Regarding latency, the short-range setup measured 0.3 seconds, while the long-range data transfer clocked in at 1.4 seconds. The sensor's response time was approximately ten seconds.

      A path toward a realistic metaverse

      “The gustatory interface will usher in a new era of AR/VR systems featuring chemical components, allowing users to not only see and hear virtual environments but also taste them,” the research paper asserts.

      The team is currently focusing on miniaturizing the e-Taste sensing kit. They are also experimenting with a non-gel solution for delivering taste chemicals, which includes using separate pouches for water and taste fluids, and adjusting concentrations accordingly.

      Water addresses another significant issue: it helps eliminate residual chemicals in the channel connected to the tongue. After each use, water flow would internally cleanse the tubing, reducing the risk of taste contamination for future sessions.

      Insights gained from the e-Taste system could contribute to developing VR gaming systems that offer users an immersive experience, combining real taste and smell with their visual interactions in a virtual environment.

      Currently, we have an experimentally validated system demonstrating that it is indeed possible to integrate taste into virtual experiences. The next steps involve miniaturizing the entire system and standardizing the electrochemical data representing various food items and beverages.

      Furthermore, shifting to more conventional computing environments,