Meeting Abstract

12-5  Monday, Jan. 4 11:15  Extreme positive allometry of animal adhesive pads and the size-limits of adhesion-based climbing LABONTE, D; CLEMENTE, C J *; DITTRICH, A; KUO, C; CROSBY, A J ; IRSCHICK, D; FEDERLE, W; University of Cambridge; University of the Sunshine Coast; Anglia Ruskin University; University of Massachusetts Amherst; University of Massachusetts Amherst; University of Massachusetts Amherst; University of Cambridge cclement@usc.edu.au http://www.usc.edu.au/explore/structure/faculty-of-science-health-education-and-engineering/staff/dr-christofer-clemente

Organismal functions are size-dependent whenever body surfaces supply body volumes. Larger organisms can develop strongly folded internal surfaces, but area enlargement is often constrained by anatomy. Here, we study the allometry of adhesive pad area in 225 climbing animal species, covering more than seven orders of magnitude in weight. Across all taxa, pad area scaled with weight, implying a 200-fold increase of relative pad area from mites to geckos. However, scaling coefficients for pad area decreased with taxonomic level, and were consistent with isometry when evolutionary history was accounted for. Within taxa, we find that the expected size-related loss of adhesion was compensated for by increasing adhesive strength instead. Our results illustrate the size limits of adhesion-based climbing, with profound implications for large scale bio-inspired adhesives.