Fig. 6: Localised biopsy demonstration using the Helixoft-integrated microcatheter in an ex-vivo oviduct.

a Active steering of the Helixoft-integrated microcatheter. In the high-stiffness state, the microcatheter advances through the oviduct and causes unintended invasion on healthy tissue at the corner (0–2 s). The microcatheter is then switched to the low-stiffness state under the R-field, enabling magnetic steering under the S-field (2–16 s). Finally, the microcatheter is switched to the medium-stiffness state and continues advancing through the corner (16–37 s). b Localised biopsy of the Helixoft-integrated microcatheter. In the medium-stiffness state, the microcatheter buckles upon contact with the target tissue (0–2 s). After switching back to the high-stiffness state (4–8 s), it successfully penetrates the target tissue (11 s). The black arrow indicates the advancement direction. Scale bars: 3 mm.