Fig. 3

Silica surfaces with reentrant and doubly reentrant cavities immersed in hexadecane. a–d Computer-enhanced isometric reconstructions of the hexadecane-air interface (center) along with the cross-sectional views along the black dotted lines (on left and right sides of the central image) as a function of time. a, c Intruding hexadecane menisci were robustly stabilized at the edges of circular DRCs and RCs (Supplementary Figure 8). b, d In contrast, DRCs and RCs with square shape failed at the corners much faster leading to the loss of trapped air. The stability of the liquid meniscus resting on the edges of the DRCs and RCs was lower if the corners were sharp (Supplementary Figure 7). e A semi-quantitative plot demonstrates the efficacy of circular DRCs and RCs in sustaining trapped air for > 3 orders of magnitude longer than square DRCs and RCs, and >7 orders of magnitude longer than commensurate SCs. (Scale bars: 200 µm)