He⁺ FIBID-fabricated 3D AFM tip architectures: an exploratory study of hollow pillars, helices, and spirals

• Alba Arroyo-Fructuoso,
• Ana Galet,
• Gregor Hlawacek and
• Rosa Córdoba

Beilstein J. Nanotechnol. 2026, 17, 863–871, doi:10.3762/bjnano.17.62

• required. Keywords: 3D-printed tips; AFM tips; beam induced nanomanufacturing; focused ion beam induced deposition (FIBID); helium ion microscope; nanohelix; nanopillar; nanospiral; scanning tip microscopy; surface topography; tungsten carbide; Introduction The atomic force microscope (AFM) is a

• μm and an approximate tip radius of 23 nm. Nanopillar structures span a broader height range, from 0.22 to 3.19 μm, with a similar tip radius of about 23 nm. Nanospiral tips are shorter, with heights between 0.05 and 0.22 μm, and exhibit a smaller approximate tip radius of 15 nm. Because of the

• exhibited distinct degradation behaviours. Hollow nanopillars showed a higher tendency to fracture during the initial approach, consistent with the larger bending moments expected for slender vertical structures. Nanospiral tips were more susceptible to progressive geometric deformation. Nanohelices showed