a Device structure and b cross-sectional transmission electron microscope (TEM) image of the fabricated dynamic memristor, consisting of a vertically stacked structure of Ti/TiOx/TaOy/Pt (50 nm/16 nm/30 nm/50 nm). c Corresponding elements distribution profile from energy-dispersive spectroscopy. d Device I–V hysteresis curves. Three scans were repeated, and the arrows indicate the direction of the voltage scan. e The experiment exploring the dynamic characteristics of device. Here the input sequence is a periodic signal composed of a write voltage pulse (3.0 V, 1 ms) followed by several read voltage pulses (1.9 V, 10 μs) in one period. The responding current is recorded for subsequent analysis. f The current decay with time follows a simple exponential relationship and the characteristic time t0 obtained by fitting is 400 μs.