This book describes the essential requirements for the realization of neuromorphic systems, where memristive devices play a key role. A comprehensive description to organic memristive devices, including working principles and models of the function, preparation methods, properties and different applications is presented. A comparative analysis of organic and inorganic systems is given. The author discusses all aspects of current research in organic memristive devices: fabrication techniques, properties, synapse mimicking circuits, and neuromorphic systems (including perceptrons), etc. Describes requirements of electronic circuits and systems to be considered as neuromorphic systems; Provides a single-source reference to the state-of-the-art in memristive devices as key elements of neuromorphic systems; Provides a comparative analysis of advantages and drawbacks between organic and inorganic devices and systems; Includes a systematic overviewof organic memristive devices, including fabrication methods, properties, synapse mimicking circuits, and neuromorphic systems; Discusses a variety of unconventional applications, based on bio-inspired circuits and neuromorphic systems.