Sustainable high-pressure light-driven water pump with a spiral tube structure and Büttiker–Landauer ratchet

Abstract

Developing sustainable water transportation technology is essential for solving water shortage problems. In this study, we proposed a sustainable high-pressure light-driven water pump that used a spiral tube structure (where light hit one side and shadowed the other) with a Büttiker–Landauer (BL) ratchet. Moreover, we examined the performance of this water pump. By using a polyurethane tube with a diameter of 2.5 mm and a length of 5 m, we demonstrated that the light-driven BL pump lifted water from a water source against the force of gravity, transported it horizontally along the spiral tube, and removed it from the tube against the surface tension. In particular, by the height scale-up design, we observed ∼800 times larger actual pressure difference ([Formula: see text] Pa) than the previous light-driven BL pump along with the pumping flow velocity up to 2.4 mm/s. In addition, by proposing a model that considers the effect of the transportation of heat energy from the hot region to the cold region, we explain the experimentally observed self-adjustment phenomenon for a flow velocity. Since our pump can work under sunlight without using electricity or fossil fuels, it is more sustainable than other pumps. Our findings should contribute to practical sustainable water transportation.