Neutral-Current Nanomotors: Using Charge-Insensitive Transport to Drive π–Metal–π Rotors

Build an integrated nanofluidic–mechanical system where neutral molecular flux through ultra-narrow channels (2–4 nm) is coupled to a π–M–π rotor (e.g., a metal-bridged benzene–benzene or CNT–fullerene joint) to generate torque. The rotor could be embedded at the interface of a nanochannel and a carbon nanotube gear train, so that pressure or field-driven neutral transport actuates rotation. This approach leverages the anomalous transport behavior of neutral molecules in ultra-nanoconfined channels, where they behave as if carrying an effective charge, producing surface-coupled electrohydrodynamic stresses that can be rectified into mechanical work. This motor concept is robust to ionic strength and pH, enabling operation in complex biological or industrial media, and offers tunable gating via the sharp diffusivity drop near 2–4 nm. Potential applications include chemo-mechanical transducers, pumps at the single-molecule scale, controlled drug release, autonomous nanorobotics, and energy harvesting in challenging environments.

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