Abstract
In contrast to synthetic materials, materials produced by organisms are formed in ambient conditions and with a limited selection of elements. Nevertheless, living organisms reveal elegant strategies for achieving specific functions, ranging from skeletal support to mastication, from sensors and defensive tools to optical function. Using state-of-the-art characterization techniques, we present a biostrategy for strengthening and toughening the otherwise brittle calcite optical lenses found in the brittlestar Ophiocoma wendtii. This intriguing process uses coherent nanoprecipitates to induce compressive stresses on the host matrix, functionally resembling the Guinier–Preston zones known in classical metallurgy. We believe that these calcitic nanoparticles, being rich in magnesium, segregate during or just after transformation from amorphous to crystalline phase, similarly to segregation behavior from a supersaturated quenched alloy.
| Original language | English |
|---|---|
| Pages (from-to) | 1294-1298 |
| Number of pages | 5 |
| Journal | Science |
| Volume | 358 |
| Issue number | 6368 |
| DOIs | |
| State | Published - 8 Dec 2017 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2017, American Association for the Advancement of Science. All rights reserved.
Funding
Helpful scientific discussions with P. Fratzl are acknowledged with thanks. We also thank M. Kalina for help in preparing the TEM samples and M. D'Incau and H. Gourkar (Anton-Paar Pvt. Ltd. India) for help during some of the microindentation experiments. The x-ray diffraction and nanoCT measurements described in this paper were carried out at beamlines ID13, ID22, and ID16B of the European Synchrotron Radiation Facility (Grenoble, France). This work was primarily supported by the Alon Fellowship for Outstanding Young Researchers of the Israeli Council for Higher Education (B.P.) and the RBNI Technion. N.M.P. is supported by the European Commission H2020 under the Graphene Flagship Core 1 no. 696656 (WP14 “Polymer Composites”), under the Future and Emerging Technologies Proactive “Neurofibres” no. 732344, and by Fondazione Caritro under “Self-Cleaning Glasses” no. 2016.0278 to L.K. P.U.P.A.G. acknowledges NSF grant DMR-1603192 and U.S. Department of Energy (DOE) grant DE-FG02-07ER15899. PEEM experiments were done at the Advanced Light Source, which is a DOE Office of Science User Facility supported by grant DE-AC02-05CH11231. The geological dolomite sample was provided courtesy of R. Slaughter (Univ. of Wisconsin, Geology Museum).
| Funders | Funder number |
|---|---|
| Alon Fellowship for Outstanding Young Researchers of the Israeli Council for Higher Education | |
| DOE Office of Science | |
| European Commission H2020 | |
| RBNI Technion | |
| National Science Foundation | DMR-1603192 |
| U.S. Department of Energy | DE-FG02-07ER15899 |
| Office of Science | DE-AC02-05CH11231 |
| Horizon 2020 Framework Programme | 732344 |
| European Commission | 696656 |
| Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology | |
| Fondazione Cassa Di Risparmio Di Trento E Rovereto | 2016.0278 |