An artifical synapse based on graphene field-effect transistor with silver gel/polarized-aptamer gate

Abstract In this work, we present an artificial synapse based on side-gate graphene-field-effect-transistor (GFET) using biocompatible silver gel/polarized-aptamer as gate dielectric. The gate functions as the presynaptic membrane, while the drain works as postsynaptic membrane. Various synaptic plasticities, including short-term enhancement (STE), short-term depression (STD), long-term potentiation (LTP), long-term depression (LTD) and the transformation from short-term plasticity to long-term plasticity have been emulated by the GFET artificial synapse. A model based on the function of a difference of two exponentials that is widely used to model the biological synapses is proposed, well fitting the behavior of the fabricated artificial synapses under different presynaptic spikes. With a fixed current of −1 μA applied to postsynaptic membrane, the excitatory-postsynaptic-potential-like spikes can be generated at postsynaptic membrane under the positive spikes applied to presynaptic membrane, suggesting the similarities between the artificial and biological synapses.