Third online CiLST seminar: Dr. Linus Stegbauer from University of Stuttgart talked about “The chiton tooth stylus: from discovery of a Fe-PO4 biomineral in its chitinous tissue to development of inks for additive manufacturing“

The third online seminar in preparation of our planned DFG Priority Program on “Chito-Materials in Life Sciences and Technologies - CiLST” was given today by Dr. Linus Stegbauer from University of Stuttgart, on invitation by Prof. Ingrid Weiß. He presented to the online auditorium the equally wide-spread and widely unknown Cryptochiton stelleri, the Giant Western Fiery Chiton (Rote Riesenkäferschnecke). This mollusk possesses a “tongue” with ca. 100 chitinous teeth, the material properties of which are the topic of Dr. Stebauer’s research. Not unexpectedly, these teeth have a complex architecture, with a core of α-crystalline chitin fibers possibly covered by an ultrathin layer of proteins (or, rather, single β-sheets), embedded in and covered by a mineralized matrix of surprising hardness and stiffness (much harder than our teeth), allowing the animals to even erode the rocks on which they graze. As a material scientist, Dr. Stegbauer investigated on a nanoscopic scale the mechanical properties of the different biomineralized organic-inorganic chitin-magnetite composite materials he found in the teeth, revealing an amazingly broad variation of hardness and elasticity. According to him, these include materials with record properties never found before in nature. Towards the end of his fascinating seminar, he then presented his current work of using biomineralized chitosan for 3D-printing of biomimetic materials. While nature appears to rely mainly on chitin, biotechnologists are rather using chitosan for its better solubility and, hence, easier handling. And of course – outlook to the future – because of the enormous range of material properties found in chitosans (plural) with different degrees of polymerization and acetylation.