Neural-inspired artificial synapses based on low-voltage operated organic electrochemical transistors

Artificial synaptic devices that emulate the neural functionalities of the human brain have received research attention owing to their inherent ability to build brain-like computing systems with faster data-processing speeds and storage capabilities at low voltages. This emerging technology is a promising approach for overcoming the bottlenecks of the conventional von Neumann architecture, such as low data-processing speed and high power consumption owing to the physical separation of processing and storage units. Among the many candidates for artificial synaptic devices, organic electrochemical transistors have been intensively investigated because they enable high transconductance, large current modulation ratios, and lower operating voltages. This review focuses on recent advancements in device fabrication strategies and the working principles adopted in designing low-voltage organic electrochemical transistors for artificial synapses. First, the fundamental concepts of synaptic behavior, such as synaptic plasticity, and essential prerequisite for artificial synapses to emulate biological synapses are reviewed. Furthermore, an overview of recent developments in organic electrochemical transistors for artificial synapses, their applications, current challenges, and future opportunities are discussed.