Fig. 4: Working performances of ion-beam-induced-film-wetting.

a Tapping mode atomic force microscope image of the front 7 μm of a 28 μm × 1 μm ionic liquid film. The height profile at y = 4.9 μm is projected onto the x-z plane, and the height profile at x = 5.2 μm is projected onto the y-z plane. b The rewritable test results of IBFW method on the same substrate. The same micro hole is adopted to guarantee all experiments are conducted at the same place of the same substrate. The induced film lengths of a 20 μm × 1 μm scan pattern keep constant throughout 10 times of rewritable tests. c The liquid film line width and thickness compared with published results^23,24. The inset show part of the IBFW liquid film imaged by AFM. The corner radiuses between the fabricated liquid film and reservoir are compared in (d) with the inset illustrates a IBFW film with corner radius down to 20 nm. e The flow velocities at different liquid film lengths are compared with literatures^23,24. The data of IBFW are presented as mean ± s.d. n = 5. f System free energy scenario of a liquid film with different film thickness, and a comparison of different flow control strategies. The left vertical axis represents the ratio that different energy terms contribute to the total free energy. The yellow vertical line represents capillary length and the red vertical line represents overlapping length (\({\lambda }_{{{{{{\rm{overlapping}}}}}}} \sim \sqrt{\frac{{A}_{{slv}}}{\gamma }}\)). Different symbols represent different strategies, the IBFW pushes the limit towards nanoscale while most counterparts fall in the surface tension region.