Keerthi, AshokGoutham, SolletiYou, YiIamprasertkun, Pawin; orcid: 0000-0001-8950-3330Dryfe, Robert A. W.; orcid: 0000-0002-9335-4451Geim, Andre K.; orcid: 0000-0003-2861-8331Radha, Boya; orcid: 0000-0003-1345-7029; email: radha.boya@manchester.ac.uk2021-05-252021-05-252021-05-252020-11-13Nature Communications, volume 12, issue 1, page 3092http://hdl.handle.net/10034/624697From Springer Nature via Jisc Publications RouterHistory: received 2020-11-13, accepted 2021-04-20, registration 2021-04-26, pub-electronic 2021-05-25, online 2021-05-25, collection 2021-12Publication status: PublishedFunder: RCUK | Engineering and Physical Sciences Research Council (EPSRC); doi: https://doi.org/10.13039/501100000266; Grant(s): EP/S017593/1Funder: Royal Society; doi: https://doi.org/10.13039/501100000288; Grant(s): URF\R1\180127, RGS\R2\202036Funder: EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council); doi: https://doi.org/10.13039/100010663; Grant(s): 852674 - AngstroCAPFunder: Ramsay Memorial FellowshipAbstract: Membrane-based applications such as osmotic power generation, desalination and molecular separation would benefit from decreasing water friction in nanoscale channels. However, mechanisms that allow fast water flows are not fully understood yet. Here we report angstrom-scale capillaries made from atomically flat crystals and study the effect of confining walls’ material on water friction. A massive difference is observed between channels made from isostructural graphite and hexagonal boron nitride, which is attributed to different electrostatic and chemical interactions at the solid-liquid interface. Using precision microgravimetry and ion streaming measurements, we evaluate the slip length, a measure of water friction, and investigate its possible links with electrical conductivity, wettability, surface charge and polarity of the confining walls. We also show that water friction can be controlled using hybrid capillaries with different slip lengths at opposing walls. The reported advances extend nanofluidics’ toolkit for designing smart membranes and mimicking manifold machinery of biological channels.Licence for this article: http://creativecommons.org/licenses/by/4.0/Article/639/301/119/544/639/925/918/1053/639/925/927/351/639/925/357/1018/120/142/126/128articlearticle2021-05-25