Hybrid 3D/Inkjet-Printed Organic Neuromorphic Transistors

Abstract

Organic electrochemical transistors (OECTs) are proving essential in bioelectronics and printed electronics applications, with their simple structure, ease of tunability, biocompatibility and suitability for different routes to fabrication. OECTs are also being explored as neuromorphic devices, where they emulate characteristics of biological neural networks through co-location of information storage and processing on the same unit, overcoming the von Neumann performance bottleneck. To achieve the long-term vision of translating to inexpensive, low-power computational devices, fabrication needs to be feasible with adaptable, scalable digital techniques. Here we show a hybrid direct-write additive manufacturing approach to fabricating OECTs. We combine 3D printing of commercially available printing filament to deliver conducting and insulating layers, with inkjet printing of a semi-conducting thin films to create OECTs. These printed OECTs show depletion mode operation paired-pulse depression behaviour and evidence of adaptation to support their translation to neuromorphic devices. These results show that a hybrid of accessible and design-flexible AM techniques can be used to rapidly fabricate devices that exhibit good OECT and neuromorphic performances.