Chinese scientists develop artificial tongue to measure spiciness

Chinese scientists have developed a new 'artificial tongue' capable of objectively measuring spiciness. The device, created by a team at the East China University of Science and Technology (ECUST), offers an unbiased alternative to human tasters, while avoiding the discomfort associated with testing hot foods.

The invention — detailed in the journal ACS Sensors — replaces taste buds with a soft, flexible gel made from milk powder, acrylic acid, and choline chloride. The design mimics the way milk soothes a burning palate. When the gel encounters capsaicin (the heat source in peppers), the embedded milk proteins bind to the compound and swell into clusters. This reaction blocks the flow of ions, causing a drop in electrical current that the device translates into a precise spiciness reading within 10 seconds.

To validate the technology, the team tested eight different chili peppers, establishing a spiciness scale from 0 (bland) to 70 (extremely spicy). The results closely matched assessments provided by trained human panelists. The device is also capable of measuring the pungency of other foods, including onions, garlic, and ginger.

The study's corresponding author, Professor Hu Jing, emphasizes that the technology opens the door for wide-ranging applications, from food quality control to medical treatment. The researchers also believe this 'bionic tongue' could finally solve a major gap in robotics, potentially integrating with AI to give humanoid robots a functional sense of taste.