Multi-Barrel Nanopipets as a Model System for Quantifying Interpore Interactions and Superadditive Transport

Developing advanced neuromorphic ionic devices requires a quantitative understanding of how neighboring nanopores interact within arrays. Crosstalk between adjacent pores is especially important because overlapping depletion zones can suppress current and cause the current through a parallel-pore array to be lower than the sum of currents through isolated pores. Here, using dual-barrel nanopipets as a model two-pore array, we show that interacting barrels connected in parallel can also produce superadditive transport, where the combined current exceeds the sum of currents through two independently measured barrels. Conductance enhancement is observed when closely spaced barrels carry opposite surface charges, with one barrel negatively charged and the other positively charged. Poisson–Nernst–Planck and Navier–Stokes continuum modeling further clarifies the role of ion concentration polarization. The models indicate that applying voltage across neighboring, oppositely charged pores creates an ion-enriched zone at the entrance of one barrel that feeds the depletion zone at the entrance of the second barrel, thereby mitigating ion concentration polarization and increasing the combined conductance. These experiments and models advance understanding of electrically and chemically addressable, interacting nanopores for future ionic circuits.