Nanochannels for low-grade energy harvesting

The exploit of low-grade energies, such as osmotic energy, thermal energy, and mechanical energy, is of great importance to alleviate the energy crisis. However, current energy harvesting technologies are generally plagued by their low efficiencies. Nanofluidic technology that based on the regulation of ion transport at the nanoscale has shown great potential in energy fields. In this review, we focus on the nanochannel-based energy harvesting, including the selectivity and permeability of the nanochannel, the theoretical output energy, and the difference between single- and multi-pore systems. Three typical energy harvesting modes are then introduced. Finally, the challenges are briefly summarized and an outlook of the nanochannel-based energy harvesting technology is provided.