Table 3 A summary table of various computing applications based on filament-free switching memristors

Artificial synapses

Planar device Li_xMos₂ with Au contacts

Phase transition

–

–

Synaptic plasticity and competition/cooperation

Bio-realistic functionality

Bio-realistic/planar device (low-scalable)

[119]

Pt/Ta₂O₅/Nb₂O_5−x/Al₂O_3−y/Ti

Electron trapping/detrapping

32 × 32

–

Long-term potentiation and depression

MNIST dataset recognition

Uniformity/High operation voltage

[90]

Ag/BaTiO₃/Nb:SrTiO₃

Ferroelectric polarization

–

–

Spike timing dependent plasticity

–

Ultrafast operation/CMOS incompatible (PLD)

[106]

PT/α-MoO₃/SrCoO_2.5/Nb:SrTiO₃

Phase transition

–

–

Long-term potentiation and depression

MNIST dataset recognition

Linear IV relationship/Large temperature dependency

[126]

Artificial neurons

Pt/anodized TiO_x/Ti

Ion migration

(V_O)

20 × 20

A resistor and a capacitor

Short-term memory, self-rectification, LIF

AMP sequence generation

Uniformity/Small ON/OFF ratio

[57]

Au/MAPbI₃/ITO

Ion migration

(V_I)

2 × 2

1 memristor, 3 resistors, 1 capacitor, 2 potentiometers, 1 comparator, 1 pulse generator

Short-term memory, LIF

SNN demonstration

Low operation voltage/CMOS incompatible (halide perovskite)

[59]

W/Pr_0.7Ca_0.3MnO₃/Pt

Filling-controlled Mott transition

16 × 3

(simulation)

1 memristor with an external measurement and pulse input system

LIF

Fisher’s iris dataset classification

Tunable firing frequency/Insufficient physical demonstration

[153]

W/WO₃/PEDOT:PSS/Pt

Ion migration

(proton)

–

2 memristors, 5 resistors, 1 capacitor, 3 potentiometers, 1 comparator, 1 timer

LIF

–

Highly bio-realistic HH neuronal dynamics/Circuit complexity

[155]

Reservoir computing

Au/WO_x/W

Ion migration

(V_O)

(88 out of) 32 × 32

Physical reservoir measured by PCB

Short-term memory, memristor dynamics

MNIST dataset classification, second-order nonlinear prediction, spoken-digit recognition, Mackey–glass prediction

Uniformity/Slow resistance change

[30, 162]

Ti/TiO_x/TaO_y/Pt

Ion migration

(V_O)

–

Physical reservoir measured by PCB

Short-term memory, memristor dynamics

Waveform classification, spoken-digit recognition, time-series prediction

Uniformity/Small dynamic current change

[31]

Planar device SnS with Cr contacts

Electron trapping/detrapping

5 × 1

Physical reservoir

Optoelectronic signal, memristor dynamics

Korean characters and sentence recognition

Ability of optoelectronic signal processing/Small dynamic current change

[23]

Selector

Pt/CoO/ITO

Electron trapping/detrapping

–

1 selector(memristor) with wire-connected resistive switching memory

Threshold switching

–

Uniformity/Slow operation speed

[93]

Self-rectifying memristor

Pt/TaO_y/nanoporous TaO_x/Ta

Ion migration

(V_O)

16 × 16

–

Self-rectification, long-term potentiation and depression

MNIST dataset recognition

Uniformity/High operation voltage

[63]

Pt/Al₂O₃/HfO₂/Ti

Electron trapping/detrapping

64 × 64

–

Self-rectification, long-term potentiation and depression

MNIST dataset recognition

Uniformity/Low programmability

[182]

Ru/Hf_0.8Si_0.2O₂/Al₂O₃/Hf_0.5Si_0.5O₂/TiN

Ion migration

(V_O)

30 × 30

–

Self-rectification, long-term potentiation and depression

Vector–Matrix Multiplication

Uniformity/Small ON/OFF ratio

[183]

Pd/HfO₂/WO_x/W

Ion migration

(V_O)

–

–

Self-rectification, long-term memory

–

Uniformity/High operation voltage

[184]