Fig. 4
Reproduced with permission from Ref. [119]. Copyright 2019, Springer Nature
Artificial synapses and their synaptic functionalities. a Schematic illustration of biological synapses and the role of synaptic weight during the signal transmission. Reproduced with permission from Ref. [15]. Copyright 2020, John Wiley Sons. b The back-to-back memristors demonstrating synaptic competition and cooperation effect. c Different Li+ ion amount under the electrode of the memristors potentiated sequentially. d Synaptic competition effect between adjacent artificial synapses. e Li+ ion distribution for the artificial synapses exhibiting synaptic cooperation. f Distinctive conductance change of the device2 for the different Li+ ion configuration.