A piezo-tribo-pyroelectric artificial tongue for multimodal gustation and temperature perception

Artificial taste sensing holds promise for advancing robotics and food science, offering automated and objective flavor analysis. However, its practical use has been constrained by limited detection mechanisms and external power dependencies, particularly a lack of integrated temperature detection. Here, we develop a piezo-tribo-pyroelectric and self-powered artificial tongue based on a flexible polyimide substrate with a cantilever-beam structure. It incorporates a layered material design, including aluminum, polyvinylidene fluoride, and fluorinated ethylene propylene, which enables autonomous operation by synergistically combining piezoelectric, triboelectric, and pyroelectric effects. The system demonstrated exceptional performance through machine learning, achieving 99.7% accuracy in classifying a range of liquids at a constant temperature and maintaining a 97.9% accuracy for liquid temperature recognition under variable thermal conditions, which have successfully accomplished multi-modal and highly sensitive perceptual capabilities. These findings indicate that our design effectively overcomes existing key limitations, suggesting promising applications in robotics for liquid identification, food and beverage quality monitoring, and personalized nutrition management.