Researchers have invented an “artificial tongue” that can accurately detect and measure the spice level of foods without putting one's taste buds at risk, according to a news release from the American Chemical Society.
The invention could be used to accurately gauge the taste profile of foods and by people with impairments like ageusia, or loss of taste, according to the society.
Building on the concept of using casein proteins in milk, which bind to spicy compounds, helping to neutralize their burning, the researchers created a gel film using acrylic acid, choline chloride, and skim milk powder, then exposing it to UV light. The researchers posited that when capsaicin, the compound in peppers that creates a burning sensation in the mouth, was added to the gel, it would form hydrophobic complexes and create other changes that would decrease its ionic conductivity, according to the researchers.
When researchers added capsaicin to the artificial tongue, the gel’s electrical current decreased. In addition to detecting capsaicin, the artificial tongue detected sharp and pungent notes as well, including those from black pepper, garlic, horseradish, and onion.
“The artificial tongue enables pungent compounds to be detected over a wide range (0.0001–1 wt %) with high sensitivity (0.259 wt %–1) and fast response times (<10 s). Moreover, our artificial tongue can detect the pungency degree in a variety of spicy foods and condiments with intertranslatable ionic currents,” wrote the researchers (ACS Sensors, October 29, 2025), led by Weijun Deng.
To help validate the tongue’s accuracy, the research team then had a panel of taste testers sample and rate eight types of peppers and foods, including hot sauces, rating their spiciness. The results were comparable, according to the researchers.
“Our flexible artificial tongue holds tremendous potential in spicy sensation estimation for portable taste-monitoring devices, movable humanoid robots, or patients with sensory impairments like ageusia, for example,” Deng said in the release.
