Rapid-responsive and water-stable organic electrochemical transistors enabled by supramolecular artificial ion channels

Directly coupling ionic fluxes to volumetric electronic transduction, organic electrochemical transistors (OECTs) emulate ion-based natural signalling mechanisms and blur the boundary between abiotic electronics and living systems. However, uncontrolled water infiltration into mixed ionic–electronic (semi)conductors slows their response and compromises operational stability in physiological environments. Here, inspired by cell membranes, which precisely regulate ion and water transport through a spatially segregated dual architecture, we develop a supramolecular artificial ion-channel material. Comprising hydrogen-bonded crown ether stacks assembled within a fluorinated polymer matrix, the resulting material combines high ionic conductivity with low water permeability. OECTs operating with the ion-channel layer exhibit simultaneously enhanced temporal response and aqueous stability. Our strategy is applicable to p-type and n-type semiconductors and maintains uniform performance in high-density transistor arrays. When implanted in the rat brain, the OECT devices achieve real-time, high-fidelity monitoring of dopamine dynamics in chronic settings. By resolving the long-standing water-instability bottleneck, our approach advances OECTs towards closed-loop adaptive modulation and biohybrid computing. The slow response and water instability of current organic electrochemical transistors (OECTs) hinder their in vivo applications. OECTs with a layer of assembled stacks of crown ethers within a water-resistant polymer show fast response and stability, achieving real-time, high-fidelity monitoring of neural activities under physiological conditions.