Figure 2.

(a) Across all instars, whole-body adhesive performance scaled as m^0.69 (95% CI: 0.59–0.79, n = 45; dotted line), whereas adhesive forces measured with perpendicular pull-offs of individual pads scaled as m^0.34 (95% CI: 0.27–0.40, n = 72; solid line). The discrepancy arises from the absence of shear forces during perpendicular pull-offs. When shear forces scaled with pad area were applied prior to detachment, adhesive forces scaled as m^0.71 (95% CI: 0.61–0.82, n = 32; dashed line). More detailed statistics can be found in the main text. (b) Because of the linear relationship between applied shear force and measured adhesion, applying a shear force corresponding to the insect’s body weight increases the scaling coefficient of adhesion, leading to an apparent increase in pad efficiency. When shear forces equivalent to one body weight were applied prior to detachment, adhesive stress increased with m^0.31 (95% CI: 0.16–0.45, n = 23), sufficient to achieve size-independent safety factors. Note that both plots are double-logarithmic. (Online version in colour.)