Figure 1.

Surface morphologies of ordered phage films assembled from a phage solution (1 × 10¹⁴ pfu mL⁻¹) at different pulling speeds by the dip-pulling method. The surface morphologies were observed by a bright field optical microscopy imaging at a low magnification and by AFM imaging at a high magnification (shown as insets). a–d) The optical imaging of the film structures at different pulling speeds: a) 10 μm s⁻¹; b) 4 μm s⁻¹; c) 1.5 μm s⁻¹; d) 0.5 μm s⁻¹). The red bar on the images indicated the average width (D₁) of the microridges at different speeds. As the speed decreased, the width (D₁) of the microridges became smaller. e–g) AFM images of a NiM structure at different magnifications showing the microridges/microvalleys and nanoridges/nanogrooves (schematically shown in Scheme 1d). The red arrow denotes the pulling force direction. h,i), Relationship between the pulling speed and the six size parameters of the NiM (D₁, D₂, w₁, w₂, d₁, d₂). The length of d₁ didn’t change with the speeds because it reflects the phage length, while the other five factors showed an increase (D₁, d₂) or a decrease (D₂, w₁, w₂).