  Memristive materials are related to neuromorphic applications as they can
combine information processing with memory storage in a single computational
element, just as biological neurons. Many of these bioinspired materials
emulate the characteristics of memory and learning processes that happen in the
brain. In this work, we report the memristive properties of a two-terminal
(2-T) organic device based on ionic migration mediated by an ion-transport
polymer. The material possesses unique memristive properties: it is reversibly
switchable, shows tens of conductive states, presents Hebbian learning
demonstrated by spiking time dependent plasticity (STDP), and behaves with both
short- (STM) and long-term memory (LTM) in a single device. The origin and
synergy of both learning phenomena were theoretically explained by means of the
chemical interaction between ionic electrolytes and the ion-conductive
mediator. Further discussion on the transport mechanism was included to explain
the dynamic behaviour of these ionic devices under a variable electric field.
We propose this polymer-based composite as an outstanding neuromorphic material
for being tunable, cheap, flexible, easy to process, reproducible, and more
biocompatible than their inorganic analogues.
