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

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.