Organic Electrochemical Transistors Monolithically Integrated with Precise Micro-Dispensing Enable High-Performance...

Organic electrochemical transistors (OECTs) are key components in advanced bioelectronics, wearable devices, and neuromorphic biointerfaces. However, to fully unlock their potential and facilitate widespread adoption, the development of high-performance OECTs and their seamless integration into circuits is essential, yet still limited. In this work, the monolithic integration of OECTs and OECT-based amplifiers, fabricated entirely on flexible substrates using high-resolution micro-dispensing, is reported. This additive method enables precise deposition of conductors, semiconductors, insulators, and electrolytes across a wide viscosity range (10 -10⁵ cP) with micrometer-scale resolution and femtoliter-volume control. The resulting transistors achieve a record intrinsic gain of 330 V/V and form the basis for fully printed amplifier circuits with a maximum voltage gain of 77.5 and a supply-normalized gain of 193.7 V^-1. These amplifiers demonstrate a gain-bandwidth product of 1 MHz - the highest reported for fully printed OECTs - and enable real-time acquisition and amplification of electrooculography (EOG) signals with minimal distortion. This work establishes micro-dispensing as a scalable and reliable method for manufacturing high-performance printed bioelectronic circuits, bridging the gap between low-cost fabrication and the performance requirements of next-generation bioelectronics.