Force curve “sawtooths” in the retraction (blue) and the approach (red) force traces taken from the adhesive of the terrestrial green algae Prasiola linearis. For this bioadhesive it is not unusual to see up to 40 sawtooth responses within a single pulling measurement. This may be attributed to the mechanical response to the unravelling of individual protein molecules cross-linked into intermolecular sheets within an amyloid quaternary structure. For more information, see “Beneficial characteristics of mechanically functional amyloid fibrils evolutionarily preserved in natural adhesives,” published in Nanotechnology, 12, December 2006.

Image courtesy of A. Mostaert and S. Jarvis, Trinity College Dublin, Ireland.