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Abstract Organic electrochemical transistors (OECTs) are ideal devices for translating biological signals into electrical readouts and have applications in bioelectronics, biosensing, and neuromorphic computing. Despite their potential, developing programmable and modular methods for living systems to interface with OECTs has proven challenging. Here we describe hybrid OECTs containing the model electroactive bacteriumShewanella oneidensisthat enable the transduction of biological computations to electrical responses. Specifically, we fabricated planar p-type OECTs and demonstrated that channel de-doping is driven by extracellular electron transfer (EET) fromS. oneidensis. Leveraging this mechanistic understanding and our ability to control EET flux via transcriptional regulation, we used plasmid-based Boolean logic gates to translate biological computation into current changes within the OECT. Finally, we demonstrated EET-driven changes to OECT synaptic plasticity. This work enables fundamental EET studies and OECT-based biosensing and biocomputing systems with genetically controllable and modular design elements. 

Abstract The measurement of mobility and threshold voltage in thin‐film transistors (TFTs) in which the mobility is a function of gate voltage or carrier density is usually done inaccurately. Herein, accurate mobility calculations within the framework of the gradual channel approximation are described. Conventionally, the derivative of drain current with respect to gate voltage is often used to calculate mobilities in the linear region. This procedure often leads to errors when the mobility is not constant. Using a first‐order finite difference‐based calculations, it is shown how the correct field‐effect mobility can be extracted. The corrected mobility can be smaller than the conventionally calculated field‐effect mobility by up to a factor of 2. It is also shown that the corrected field‐effect mobility is identical to the average mobility. A threshold voltage that is independent of gate voltage value and suitable for disordered semiconductors is used for more accurate mobility calculations. The mobility and threshold voltage calculations are illustrated with experimental data from multiple TFTs with indium gallium zinc oxide, zinc tin oxide, and molybdenum disulfide channel layers.