title: Base plate mechanics of the barnacle Balanus amphitrite (=Amphibalanus amphitrite).
abstract: The mechanical properties of barnacle base plates were measured using a punch test apparatus, with the purpose of examining the effect that the base plate flexural rigidity may have on adhesion mechanics. Base plate compliance was measured for 43 Balanus amphitrite (=Amphibalanus amphitrite) barnacles. Compliance measurements were used to determine flexural rigidity (assuming a fixed-edge circular plate approximation) and composite modulus of the base plates. The barnacles were categorized by age and cement type (hard or gummy) for statistical analyses. Barnacles that were 'hard' (> or =70% of the base plate thin, rigid cement) and 'gummy' (>30% of the base plate covered in compliant, tacky cement) showed statistically different composite moduli but did not show a difference in base plate flexural rigidity. The average flexural rigidity for all barnacles was 0.0020 Nm (SEM +/- 0.0003). Flexural rigidity and composite modulus did not differ significantly between 3-month and 14-month-old barnacles. The relatively low flexural rigidity measured for barnacles suggests that a rigid punch approximation is not sufficient to account for the contributions to adhesion mechanics due to flexing of real barnacles during release.
authors.affiliation: U.S. Naval Research Laboratory, Washington, District of Columbia, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Ramsay
authors.forename: Gary H
authors.initials: GH
authors.lastname: Dickinson
authors.forename: Beatriz
authors.initials: B
authors.lastname: Orihuela
authors.forename: Daniel
authors.initials: D
authors.lastname: Rittschof
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Wahl
mesh_terms: D000268:Adhesiveness; D000818:Animals; D001696:Biomechanical Phenomena; D007814:Larva / Q000254:growth & development; D008954:Models, Biological; D013499:Surface Properties; D001468:Thoracica / Q000254:growth & development*