Enhancing the performance of a cylindrical nanopore in osmotic power generation through designing the waveform of its inner surface†

Recently, nanofluidic osmotic power, a promising technology converting the salinity difference between brine and fresh water into electricity using nanopores, has drawn the attention of researchers. Previous studies in this field were based mainly on nanopores having a smooth inner surface. To enhance the performance of nanofluidic osmotic power, we investigated four types of cylindrical nanopores, each with a unique waveform wall design (square, saw-tooth, triangle, and sine waves). This study focused on elucidating the influence of bulk salt concentration and geometric characteristics at the solid–liquid interface. We demonstrated that the presence of a waveform wall introduces new variables that have a significant impact on the overall performance of a nanofluidic osmotic power system. At the optimal amplitude of the waveform wall, raising waveform frequency can remarkably improve the osmotic current, diffusion potential, maximum power, and maximum efficiency. The present study provides a novel aspect of osmotic power, where the geometric nature of the nanopore reveals profound and intriguing phenomena primarily attributed to the distribution of ions within its interior.