2011/08/24 by Ping Yuan Hsu, Liehui Ge, Xiaopeng Li +4 · 1 citation
Biochemistry, Genetics and Molecular Biology · Chemistry · Engineering · Physics and Astronomy · #Adhesion #Adhesion, Friction, and Surface Interactions #Atomic force microscopy #Biology #Biophysics #Chemistry #Composite material #Ecology #Force Microscopy Techniques and Applications #Force spectroscopy #Gecko #Insect and Arachnid Ecology and Behavior #Materials science #Molecule #Nanotechnology #Organic chemistry #Seta #Substrate (aquarium) #van der Waals force
paper · pdf · doi:10.1098/rsif.2011.0370
openalex publication_date 2011/08/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Observers ranging from Aristotle to young children have long marvelled at the ability of geckos to cling to walls and ceilings. Detailed studies have revealed that geckos are 'sticky' without the use of glue or suction devices. Instead, a gecko's stickiness derives from van der Waals interactions between proteinaceous hairs called setae and substrate. Here, we present surprising evidence that although geckos do not use glue, a residue is transferred on surfaces as they walk-geckos leave footprints. Using matrix-free nano-assisted laser desorption-ionization mass spectrometry, we identified the residue as phospholipids with phosphocholine head groups. Moreover, interface-sensitive sum-frequency generation spectroscopy revealed predominantly hydrophobic methyl and methylene groups and the complete absence of water at the contact interface between a gecko toe pad and the substrate. The presence of lipids has never been considered in current models of gecko adhesion. Our analysis of gecko footprints and the toe pad-substrate interface has significant consequences for models of gecko adhesion and by extension, the design of synthetic mimics.