Temporal Feature and Flexible Modulation in Artificial Synapses Realized by a Combination of Phase Transition and Asymmetric Electric Double Layers

Neuromorphic devices are accelerating the development of brain-like computing since they are more suitable for data-intensive algorithms than von Neumann systems. However, current devices are still inferior to their biological counterparts in functional flexibility and diversity with temporal features. Here, we introduce asymmetric electric double-layer-based modulation combined with phase transition phenomena and show a nimble artificial synapse with an additional dimension (i.e., time). Flexible modulation of artificial synapses is achieved by controlling the balance between different phenomena, which means that response behavior can be altered between several modes without physical changes to the device. In the unique bipolar mode, signals triggered by a single stimulus can exhibit both potentiation and depression behavior in a chronological order. Thus, the mimicking of complex bioelectrical phenomena like the action potential can be naturally demonstrated. Our results add a flexible function and an additional degree of freedom to artificial synapses at the hardware level and may enlighten advanced neuromorphic computing.