Integrated Sensing Arrays Based on Organic Electrochemical Transistors

Organic electrochemical transistors (OECTs), as one of the most promising sensing techniques, have shown various advantages compared to traditional means, which include ultra-high sensitivity, low driving voltage, and excellent biocompatibility for different bioelectrical and biochemical sensing. Moreover, to fully unleash the potential of OECT sensors, integrated sensing systems, especially OECT-based sensing arrays, are widely investigated due to spatiotemporal resolution, mechanical flexibility, high optical transparency, low power dissipation, and ease of fabrication. These advantages are attributed to the unique working mechanism of OECT, novel mixed ionic-electronic (semi)conductors, adaptable device geometry/structure, etc. In this review, advances in OECT-based sensing systems are systematically summarized, with a focus on the OECT-based sensing array. Furthermore, perspectives, concerning stability, cut-off frequency, integrating density, and power dissipation, are discussed based on recent studies on OECTs and their relevant sensor arrays. Last, a summary and an outlook of this field are provided.