Memristors with Nociceptor Characteristics Using Threshold Switching of Pt/HfO₂/TaOx/TaN Devices

As artificial intelligence technology advances, it is necessary to imitate various biological functions to complete more complex tasks. Among them, studies have been reported on the nociceptor, a critical receptor of sensory neurons that can detect harmful stimuli. Although a complex CMOS circuit is required to electrically realize a nociceptor, a memristor with threshold switching characteristics can implement the nociceptor as a single device. Here, we suggest a memristor with a Pt/HfO₂/TaO_x/TaN bilayer structure. This device can mimic the characteristics of a nociceptor including the threshold, relaxation, allodynia, and hyperalgesia. Additionally, we contrast different electrical properties according to the thickness of the HfO₂ layer. Moreover, Pt/HfO₂/TaO_x/TaN with a 3 nm thick HfO₂ layer has a stable endurance of 1000 cycles and controllable threshold switching characteristics. Finally, this study emphasizes the importance of the material selection and fabrication method in the memristor by comparing Pt/HfO₂/TaO_x/TaN with Pt/TaO_x/TaN, which has insufficient performance to be used as a nociceptor.