Polymer-based composites for engineering organic memristive devices

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.