Emulating Ebbinghaus forgetting behavior in a neuromorphic device based on 1D supramolecular nanofibres

Mimicking synaptic functions in hardware devices is a crucial step in realizing brain-like computing beyond the von Neumann architecture. 1D nanomaterials with spatial extensions of a few µm, similar to biological neurons, gain significance given the ease of electrical transport as well as directionality. Herein, we have reported a two-terminal optically active device based on 1D supramolecular nanofibres consisting of CS (coronene tetracarboxylate) and DMV (dimethyl viologen) forming alternating D–A donor–acceptor) pairs. These fibres self-assemble from water, are simple to process without much dependence on lithography, enable miniaturization, reduce carrier scattering, and increase charge transport. They undergo self-repair with exposure to humidity, a property that may play an important role in integration. Thus, the nanofibre device has been fabricated to emulate synaptic functions such as the STP (short-term potentiation), LTP (long-term potentiation), PPF (paired-pulse facilitation), STDP (spike-time dependent plasticity) and learning–relearning behaviors. In addition, an extensive study on the less explored Ebbinghaus forgetting curve has been carried out. The supramolecular nanofibres being light sensitive, the potential of the device as a visual system is demonstrated using a 3 × 3 pixel array.

DOI: 10.1039/d3nr00195d