Memristors Enabling Biomimetic Pain Perception Based on Pure VO ₂ Nanoplates Synthesized via Annealing of VSe ₂ Nanoplates

Monoclinic vanadium dioxide (VO2 (M)) has garnered significant attention due to its metal–insulator transition (MIT) and application potential in Mott transistors and memristive devices. Nevertheless, synthesizing stoichiometric VO2 remains challenging due to the redox instability of V4+ in VO2, which readily oxidizes to V5+ or reduces to V3+. Here, we present an attractive approach for synthesizing high-purity VO2 by thermally oxidizing two-dimensional (2D) vanadium diselenide (VSe2) nanoplates. Comprehensive characterization via Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM) confirms the formation of M1-phase VO2 with a well-defined stoichiometric ratio. The resulting VO2 nanoplates present pronounced threshold switching (TS) behavior, enabling the fabrication of robust Au/VO2/Au memristors with exceptional stability over 3,100 cycles and a switching ratio of up to 320. The devices exhibit rapid switching characteristics, achieving an on-state transition in 30 μs and off-state recovery in 20 μs, highlighting their potential for high-speed memory applications. This memristor emulates nociceptive behaviors, such as threshold detection, relaxation, and sensitization. This work provides a scalable synthesis route for VO2 nanoplates and highlights their functionality in mimicking bioinspired neuromorphic systems, paving the way for next-generation sensory applications.