An artificial olfactory system with sensing, memory and self-protection capabilities

Artificial olfactory system has been received increasing attention due to its important applications in future artificial nose, humanoid robot and next generation human-computer interface. However, it is still a challenge to completely simulate the functions of the human olfactory system recognize, remember and induce muscle movement from pungent odor. Here, we have developed a flexible artificial olfactory system by integrating Sr-ZnO-based gas sensors, HfO_x-based memristors and electrochemical actuators, which can recognize and memorize and make the self-protection action for NH₃. The Sr-ZnO gas sensor can perceive and recognize NH₃ through the change of resistance, and the signal transferred to the memristor can switch the resistance states for the storage of ammonia information. Meanwhile, the activation of memristor can also trigger the movement of the electrochemical actuator to block the gas flow channel analogous to the self-protection action of covering the nose with the hand when smelling irritating NH₃. Our artificial olfactory system provides a promising strategy for future bioinspired electronics research, especially in the field of mimicking biological sensory systems.