Fig. 1: Helium focused ion beam liquid inducing mode and working procedure of ion-beam-induced-film-wetting nano-printing.

a Phase diagram of three working modes under different HFIB dose density, manipulated by the dwell time and the scan spot density. The background color map shows the dose density ranges from 10⁻²−10⁴ions/nm². The horizontal axis corresponds to the reciprocal of the square of the scan spot spacing, s⁻², which represents the number of scan spots within 1 nm². The imaging mode exerts no influence to samples (blue squares); the inducing mode can induce directional liquid flow (red circles); and the damaging mode can etch samples and induce Helium bubbling (cyan triangle). b The hierarchical branched flow pattern of ionic liquid after a frame of HFIB scan. The IL will eventually fill the entire irradiated area in 30 s. c Contact line region of the IL reservoir and nano-patterning-and-visualization-engine pattern design. Left is a schematic diagram, and right is an HIM image. The white arrow indicates the pattern direction and area in NPVE. The dashed yellow box represents the CTL region chosen for HFIB scan. d The rectangular film pattern (50 μm × 1 μm) fabricated by IBFW. The insets are the details to manifest small corner radius and well reproduction of the design, the yellow box edges are 2 μm. e The IBFW fabricated ‘PKU COE’ pattern demonstrates its potential in on-demand printing of complex liquid film networks. f The minimal line width that IBFW can fabricate is around 106 nm.