Fig. 5. Wetting properties of the CNT-EHL fabricated surfaces. (a) Optical image sequences on the (i) flat, (ii) 90° tilted and (iii) 180° tilted CNH surface. (b) Sequence images of the water drop advancing and receding on the S2L2 surface indicating its superhydrophobic contact angle of 173°, shape of the suspending water drops and the complete receding without rupture while withdrawing the water droplet with θ _Adv ≈ θ _Rec ≈ θ _γ. This behaviour corresponds to a Cassie-Baxter wetting state. (c) Different wetting states of all the experimental samples showing the measured contact angles (right) and the measured hysteresis (left) with SNH, S1L and S2L2 exhibiting roll-off (lotus-leaf) behaviour and CNH and S2L demonstrating sticky (rose-petal) properties not observed in the case of hexagonal pillars in comparison to the reference sample of the flat PCTFE thin film. (d) Variation of the measured contact angle (blue diamonds) and the corresponding hysteresis (grey triangles) with the geometric parameters is in agreement within their error margins and are well described by the theoretical prediction (line). The theoretical data follow the same trend, but are offset towards slightly higher values. Inset: Variation of the contact angle as a function of the structures’ height. Over a height variation of 350 nm, the contact angle changed by only 22% compared to a variation as function of r/R by a factor of 7.