Generation of a net flow due to fixed oblique beam structures in the nucleate boiling region

Effective utilization of unused heat below 200 °C is essential for a sustainable society. In this study, we propose a thermally driven water pump using fixed oblique beam structures with bubbles in the nucleate boiling region (approximately, 100–130 °C). Here, the oblique beam structure breaks the symmetry of the bubble force, and thus, they provide a net flow. Specifically, by using six fixed oblique beams along a circular fluidic channel, we observed a net flow of an average flow velocity of ∼40 mm/s and an average volume flow rate of ∼10 000 mm3/s (∼0.01 l/s) at the superheat of ∼22 K. Our findings should contribute to the effective use of unused heat such as factory waste heat and environmental energy.