Organic semiconductor materials for neuromorphic and bioelectronic systems design rules and applications.

The ability of organic semiconductors to be mechanically flexible, adjustable in their electronic properties, solution processable, and biocompatible has led to their identification as key materials for Neuromorphic and Bioelectronic systems. This review summarizes the relationship between molecular design, crystallinity and charge transport mechanisms, and device performance and discusses the role of conjugated polymers, small-molecule semiconductors, and mixed ionic-electronic conductors for brain-inspired computing and biointegrated electronics. It also explores key device architectures, including organic field-effect transistors, organic electrochemical transistors, and organic memristors with a focus on their demonstration of synaptic plasticity, learning and neural signal processing. Biosensing, neural interfaces, and implantable bioelectronics are explored in terms of challenges of operational stability, scalability, and long-term biocompatibility. This review seeks to establish a framework that facilitates the development of flexible, energy-efficient, and biologically compatible electronic technologies, by combining materials design with device engineering and novel applications.