Enhancement-Mode Ionic Transistor Architecture with an Entirely Ionic Gating Mechanism

This study presents a comprehensive analysis of the development and characteristics of an ion-gated organic electrochemical transistor (IGT) architecture that utilizes an entirely ionic gating mechanism and operates within physiologically relevant voltage ranges, enabling advancements in next-generation biosensors and bioelectronic applications. The architecture dynamically mobilizes ionic species to reversibly form and dissolve ionic double layers (IDLs), enabling rapid switching between source and drain terminals. While distinct from traditional electrolyte-gated designs, the gating mechanism exhibits characteristics analogous to n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) in enhancement mode. The gating mechanism was proved functional for a range of gating potentials (25–2500 mV); in this range and for a source-drain potential difference sweeping between 0 and 3 V, the IGT exhibited a multistage drain characteristic, which is attributed to and characteristic of the ionic nature of the IGT. This proof-of-concept study details the IGT’s architecture, operational principles, and drain characteristics, showcasing its enhanced performance by integrating an ionomeric membrane, which improves baseline and peak current levels without compromising switching speed.