Charge-Engineered COFs for Biointegrated Memristor Nerves

Restoring motor function after neurological injury requires artificial neural interfaces that emulate biological rate coding with low power and stability. Here, we present a molecular-level strategy to engineer covalent organic frameworks (COFs) for biointegrated memristors as artificial efferent nerves. Leveraging intrinsic porosity and chemical tunability, we modulate ionic transport and memristive dynamics via charged group functionalization. We synthesize positively and negatively charged COF nanosheets and reveal polarity-dependent memristive behaviors. In a conductive-filament memristor architecture, negatively charged COFs enhance electrostatic interactions with mobile metal ions, more effectively regulating filament nucleation and rupture. Consequently, negatively charged devices reduce the switching voltage to 0.5 V, deliver an ON/OFF ratio > 10⁵, and lower power consumption to 0.04 nW, with suppressed leakage of ∼5 pA and stable operation over 5000 bending cycles. In vivo, the COF memristor translates neuronal spike trains into smooth, graded muscle contractions in a mouse leg, emulating physiological motor control. This work establishes charge-engineered COFs as a platform for neuromorphic and bioelectronic technologies.