简介:Thefracturetoughnessofhardbiomaterials,suchasnacre,bovinehoofwallandbeetlecuticle,isassociatedwithfibrousorlamellarstructuresthatdeflectorstopgrowingcracks.Theirhardnessandreducedmodulusweremeasuredbyusingananoindenterinthispaper.Micro/nanoscalecracksweregeneratedbynanoindentationusingaBerkovichtip.Nanoindentationofnacreandbovinehoofwallresultedinpile-uparoundtheindent.Itwasfoundthatthefracturetoughness(KC)ofbovinehoofwallisthemaximum,thesecondisnacre,andtheelytracuticleofdungbeetleistheleastone.