This technology is related to the development of a “response-behavior selective” type gas sensor that can discriminate multiple gases in a single sensor channel. The VO₂(M1) phase shows different response behavior (upward/downward) to gases such as ammonia (NH₃) and hydrogen sulfide (H₂S), enabling highly accurate identification even in gas mixtures. It can be operated at room temperature and is expected to be applied in the healthcare field.

Conventional semiconductor gas sensors rely on “response-intensity selectivity,” making it difficult to distinguish between gases with similar properties. In addition, detection of multiple gases requires a multi-channel configuration, which poses challenges to device miniaturization and low power consumption. This technology enables multi-gas discrimination with a single channel, achieving high selectivity while minimizing interference.

We propose a new sensing concept called “response behavior-selectivity,” in which identification is based on the directionality of the gas response (forward/reverse). Theoretical calculations predict the response behavior, which can be controlled by doping elements, which is unique to this technology. Furthermore, flexible sensor chips can be fabricated, making them suitable for wearable devices.

Potential applications include smart diapers that identify defecation and urination, health monitoring by exhalation, and VOC detection. In the future, we will promote development toward practical applications while further downsizing the device and improving the efficiency of signal transmission by linking it with MEMS technology and IoT.

• Response-Behavior Selectivity
• Single-Channel Multi-Gas Identification
• Vanadium Dioxide
• Element Doping
• Gas Sensors
• Room Temperature Operable Sensors
• Smart Diapers