Fig. 2: H-H neuron circuit based on NbO2 memristors and the firing behaviors.
A The H-H neuron consists of two resistors (R1, R2), two capacitors (C1, C2), and two TS devices (TS1, TS2) with opposite bias voltages provided by two voltage sources (E1, E2). B Typical volatile threshold switching behavior of two TS devices used in the H-H neurons. Both TS devices exhibit similar VTH and VHold. C Top panel: Schematic of TS devices’ switching sequence and dynamic output action potentials when the circuit behaves in a spiking feature, in which TS2’s switching-on time is behind TS1’s switching-off. Bottom panel: Schematic of TS devices’ switching sequence and the dynamic output action potentials when the circuit behaves in a bursting feature, in which TS2’s switching-on time is before TS1’s switching-off and TS2 switches twice. (Simulation) D The neuron output presents two different firing features under different input voltages. When the input is 0.7 V, the neuron fires in the spiking feature, showing regular single-spike output, and when the input is 1.2 V, the neuron fires in the bursting feature with two spikes per burst. (Experiment) E Under triangle wave scanning with an amplitude of 1.3 V, the output of the neuron shows a transition between the two firing features. When the input is ~1.0 V, the output of the neuron transitions from spiking to bursting. (Experiment) F Neuronal output frequency as a function of input voltage. The firing cluster frequency of the neuron increases linearly with increasing voltage. When the voltage input is 1.0 V, bursting starts to appear in the neuron output, corresponding to a large bursting spike frequency. (Experiment).
