Microfluidic Electronic Tongues Based on High-Entropy Nitride Films

High Resolution Image Download MS PowerPoint Slide High-entropy nitrides (HENs) are emerging as promising materials for sensing applications due to their exceptional chemical stability, diverse electrical properties, and highly tunable surface and bulk characteristics. This study integrates HEN thin films, deposited via RF sputtering, into an impedimetric microfluidic electronic tongue (e-tongue), designed to assess their potential for high sensitivity and robust detection of various analytes. The active films displayed a distinct oxide-rich surface and nitride-rich sublayer, directly influencing sensor performance. As a proof-of-concept, the unique electrical response of the HEN-based e-tongue enabled precise discrimination between similar ions (Na + and K + ) and basic human tastes (sweet, salty, bitter, umami, and sour) at concentrations near or below the human palatability threshold. Moreover, after repeated use, the films maintained their chemical and structural integrity, ensuring long-term stability and reproducibility. These results highlight the potential of HENs as versatile materials for advanced sensing applications, demonstrating their promise for next-generation e-tongue systems and expanding the range of applications for this class of materials.