title: Passive and active mechanical properties of biotemplated ceramics revisited.
abstract: Living nature and human technology apply different principles to create hard, strong and tough materials. In this review, we compare and discuss prominent aspects of these alternative strategies, and demonstrate for selected examples that nanoscale-precision biotemplating is able to produce uncommon mechanical properties as well as actuating behavior, resembling to some extent the properties of the original natural templates. We present and discuss mechanical testing data showing for the first time that nanometer-precision biotemplating can lead to porous ceramic materials with deformation characteristics commonly associated with either biological or highly advanced technical materials. We also review recent findings on the relation between hierarchical structuring and humidity-induced directional motion. Finally, we discuss to which extent the observed behavior is in agreement with previous results and theories on the mechanical properties of multiscale hierarchical materials, as well as studies of highly disperse technical materials, together with an outlook for further lines of investigation.
authors.affiliation: Chair for Biogenic Polymers, Technical University of Munich, Schulgasse 16, D-94315 Straubing, Germany. Straubing Center of Science for Renewable Resources, Schulgasse 16, D-94315 Straubing, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Van Opdenbosch
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fritz-Popovski
authors.forename: Johann
authors.initials: J
authors.lastname: Plank
authors.forename: Cordt
authors.initials: C
authors.lastname: Zollfrank
authors.forename: Oskar
authors.initials: O
authors.lastname: Paris
mesh_terms: D001696:Biomechanical Phenomena; D040761:Biomimetic Materials; D002516:Ceramics; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D053761:Nanocomposites