An anonymous reader quotes a report from IEEE Spectrum: Virtual- and augmented-reality setups already modify the way users see and hear the world around them. Add in haptic feedback for a sense of touch and a VR version of Smell-O-Vision, and only one major sense remains: taste. To fill the gap, researchers at the City University of Hong Kong have developed a new interface to simulate taste in virtual and other extended reality (XR). The group previously worked on other systems for wearable interfaces, such as haptic and olfactory feedback. To create a more “immersive VR experience,” they turned to adding taste sensations, says Yiming Liu, a coauthor of the group’s research paper published today in the Proceedings of the National Academy of Sciences.
The lollipop-shaped lickable device can produce nine different flavors: sugar, salt, citric acid, cherry, passion fruit, green tea, milk, durian, and grapefruit. Each flavor is produced by food-grade chemicals embedded in a pocket of agarose gel. When a voltage is applied to the gel, the chemicals are transported to the surface in a liquid that then mixes with saliva on the tongue like a real lollipop. Increase the voltage, and get a stronger flavor. Initially, the researchers tested several methods for simulating taste, including electrostimulating the tongue. The other methods each came with limitations, such as being too bulky or less safe, so the researchers opted for chemical delivery through a process called iontophoresis, which moves chemicals and ions through hydrogels and has a low electrical-power requirement. With a 2-volt maximum, the device is well within the human safety limit of 30 V, which is considered enough to deliver a substantial shock in some situations. Some of the possible applications mentioned by the authors include gustation tests, virtual grocery shopping, and immersive environments for exploring food flavors. However, the current system is limited to one hour of use due to gel depletion and it only supports a handful of flavor channels.
Future development aims to extend operation time, increase flavor complexity, and improve usability, marking the beginning of a new frontier for XR interfaces.