Real-time threshold voltage compensation on dual-gate electrolyte-gated organic field-effect transistors

Abstract

Electrolyte-Gated Organic Field-Effect Transistors (EGOFETs) offer many opportunities for the development of low-cost and low-power electronics suitable for applications like sensors and point-of-care tests; however, EGOFETs can be affected by the drift of their operative point that causes signals distortion and loss of information during sensing applications. Here, a blend of 2,8-Difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) and polystyrene (PS) is used as the active material for the fabrication of dual-gate EGOFETs. We exploited the dual-gate architecture to improve EGOFETs stability by implementing digital feedback that uses the back-gate electrode to compensate dynamically for the transistor threshold voltage allowing us to fix its operative point for prolonged tests (>10 h) with different aqueous solutions (Milli-Q water, NaCl 0.1 M and a physiological solution). The presented real-time threshold voltage compensation does not only allow to steady EGOFETs DC output current, but it also preserves EGOFETs sensing capability for the detection of signals with frequencies as low as 1 Hz. • Design and characterization of a dual-gate EGOFET based on diF-TES-ADT:PS: extraction of the top capacitance. • Real-time compensation of the threshold voltage on a dual-gated EGOFET. • Real-time monitoring of action potentials (frequency 1 Hz) applied to the top gate.