Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Abiotic tooth enamel


Tooth enamel comprises parallel microscale and nanoscale ceramic columns or prisms interlaced with a soft protein matrix1,2,3. This structural motif is unusually consistent across all species from all geological eras4,5,6. Such invariability—especially when juxtaposed with the diversity of other tissues—suggests the existence of a functional basis. Here we performed ex vivo replication of enamel-inspired columnar nanocomposites by sequential growth of zinc oxide nanowire carpets followed by layer-by-layer deposition of a polymeric matrix around these. We show that the mechanical properties of these nanocomposites, including hardness, are comparable to those of enamel despite the nanocomposites having a smaller hard-phase content. Our abiotic enamels have viscoelastic figures of merit (VFOM) and weight-adjusted VFOM that are similar to, or higher than, those of natural tooth enamels—we achieve values that exceed the traditional materials limits of 0.6 and 0.8, respectively. VFOM values describe resistance to vibrational damage, and our columnar composites demonstrate that light-weight materials of unusually high resistance to structural damage from shocks, environmental vibrations and oscillatory stress can be made using biomimetic design. The previously inaccessible combinations of high stiffness, damping and light weight that we achieve in these layer-by-layer composites are attributed to efficient energy dissipation in the interfacial portion of the organic phase. The in vivo contribution of this interfacial portion to macroscale deformations along the tooth’s normal is maximized when the architecture is columnar, suggesting an evolutionary advantage of the columnar motif in the enamel of living species. We expect our findings to apply to all columnar composites and to lead to the development of high-performance load-bearing materials.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Columnar motifs in biocomposites.
Figure 2: Schematic illustration of the preparation and structure of columnar biomimetic composites produced by sequential LBL infiltration of ZnO nanowires with polymers.
Figure 3: Mechanical properties of artificial columnar composites.
Figure 4: Dynamic mechanical properties of the artificial columnar composites.
Figure 5: Energy dissipation (tanδ) and load-bearing characteristics (E′/ρ) of (ZnO/LBL)n compared to manufactured materials and biocomposites.


  1. 1

    He, L. H. & Swain, M. V. Understanding the mechanical behaviour of human enamel from its structural and compositional characteristics. J. Mech. Behav. Biomed. Mater. 1, 18–29 (2008)

    Article  Google Scholar 

  2. 2

    Moradian-Oldak, J. Protein-mediated enamel mineralization. Front. Biosci. Landmark Ed. 17, 1996–2023 (2012)

    Article  Google Scholar 

  3. 3

    Palmer, L. C., Newcomb, C. J., Kaltz, S. R., Spoerke, E. D. & Stupp, S. I. Biomimetic systems for hydroxyapatite mineralization inspired by bone and enamel. Chem. Rev. 108, 4754–4783 (2008)

    CAS  Article  Google Scholar 

  4. 4

    Hwang, S. H. The evolution of dinosaur tooth enamel microstructure. Biol. Rev. Camb. Phil. Soc. 86, 183–216 (2011)

    Article  Google Scholar 

  5. 5

    Weiner, S. & Addadi, L. Design strategies in mineralized biological materials. J. Mater. Chem. 7, 689–702 (1997)

    CAS  Article  Google Scholar 

  6. 6

    Balooch, G. et al. Evaluation of a new modulus mapping technique to investigate microstructural features of human teeth. J. Biomech. 37, 1223–1232 (2004)

    CAS  Article  Google Scholar 

  7. 7

    Meyers, M. A., McKittrick, J. & Chen, P. Y. Structural biological materials: critical mechanics-materials connections. Science 339, 773–779 (2013)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Espinosa, H. D., Rim, J. E., Barthelat, F. & Buehler, M. J. Merger of structure and material in nacre and bone — perspectives on de novo biomimetic materials. Prog. Mater. Sci. 54, 1059–1100 (2009)

    CAS  Article  Google Scholar 

  9. 9

    Weaver, J. C. et al. The stomatopod dactyl club: a formidable damage-tolerant biological hammer. Science 336, 1275–1280 (2012)

    ADS  CAS  Article  Google Scholar 

  10. 10

    Jackson, A. P., Vincent, J. F. V. & Turner, R. M. The mechanical design of nacre. Proc. R. Soc. Lond. B 234, 415–440 (1988)

    ADS  Article  Google Scholar 

  11. 11

    Wang, R. Z., Suo, Z., Evans, A. G., Yao, N. & Aksay, I. A. Deformation mechanisms in nacre. J. Mater. Res. 16, 2485–2493 (2001)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Tang, Z., Kotov, N. A., Magonov, S. & Ozturk, B. Nanostructured artificial nacre. Nat. Mater. 2, 413–418 (2003)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Sarikaya, M. Biomimetics: materials fabrication through biology. Proc. Natl Acad. Sci. USA 96, 14183–14185 (1999)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Cuif, J.-P., Dauphin, Y., Nehrke, G., Nouet, J. & Perez-Huerta, A. Layered growth and crystallization in calcareous biominerals: impact of structural and chemical evidence on two major concepts in invertebrate biomineralization studies. Minerals 2, 11–39 (2012)

    CAS  Article  Google Scholar 

  15. 15

    Achrai, B. & Wagner, H. D. Micro-structure and mechanical properties of the turtle carapace as a biological composite shield. Acta Biomater. 9, 5890–5902 (2013)

    Article  Google Scholar 

  16. 16

    Wang, R. Z., Addadi, L. & Weiner, S. Design strategies of sea urchin teeth: structure, composition and micromechanical relations to function. Phil. Trans. R. Soc. Lond. B 352, 469–480 (1997)

    ADS  CAS  Article  Google Scholar 

  17. 17

    Munch, E. et al. Tough, bio-inspired hybrid materials. Science 322, 1516–1520 (2008)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Killian, C. E. et al. Mechanism of calcite co-orientation in the sea urchin tooth. J. Am. Chem. Soc. 131, 18404–18409 (2009)

    CAS  Article  Google Scholar 

  19. 19

    Cho, B.-K., Jain, A., Gruner, S. M. & Wiesner, U. Mesophase structure-mechanical and ionic transport correlations in extended amphiphilic dendrons. Science 305, 1598–1601 (2004)

    ADS  CAS  Article  Google Scholar 

  20. 20

    Erb, R. M., Libanori, R., Rothfuchs, N. & Studart, A. R. Composites reinforced in three dimensions by using low magnetic fields. Science 335, 199–204 (2012)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  21. 21

    Meaud, J. et al. Simultaneously high stiffness and damping in nanoengineered microtruss composites. ACS Nano 8, 3468–3475 (2014)

    CAS  Article  Google Scholar 

  22. 22

    Greene, L. E. et al. Low-temperature wafer-scale production of ZnO nanowire arrays. Angew. Chem. 42, 3031–3034 (2003)

    CAS  Article  Google Scholar 

  23. 23

    Podsiadlo, P. et al. Ultrastrong and stiff layered polymer nanocomposites. Science 318, 80–83 (2007)

    ADS  CAS  Article  Google Scholar 

  24. 24

    Ruan, Q. et al. Amelogenin and enamel biomimetics. J. Mater. Chem. B 3, 3112–3129 (2015)

    CAS  Article  Google Scholar 

  25. 25

    Lowenstam, H. & Weiner, S. On Biomineralization (Oxford Univ. Press, 1989)

  26. 26

    Wang, Y. C., Ludwigson, M. & Lakes, R. S. Deformation of extreme viscoelastic metals and composites. Mater. Sci. Eng. A 370, 41–49 (2004)

    Article  Google Scholar 

  27. 27

    Lakes, R. S., Lee, T., Bersie, A. & Wang, Y. C. Extreme damping in composite materials with negative-stiffness inclusions. Nature 410, 565–567 (2001)

    ADS  CAS  Article  Google Scholar 

  28. 28

    Ryou, H., Romberg, E., Pashley, D. H., Tay, F. R. & Arola, D. Nanoscopic dynamic mechanical properties of intertubular and peritubular dentin. J. Mech. Behav. Biomed. Mater. 7, 3–16 (2012)

    CAS  Article  Google Scholar 

  29. 29

    Zhang, P. & To, A. C. Highly enhanced damping figure of merit in biomimetic hierarchical staggered composites. J. Appl. Mech. 81, 051015 (2014)

    ADS  Article  Google Scholar 

  30. 30

    Hu, K., Kulkarni, D. D., Choi, I. & Tsukruk, V. V. Graphene-polymer nanocomposites for structural and functional applications. Prog. Polym. Sci. 39, 1934–1972 (2014)

    CAS  Article  Google Scholar 

  31. 31

    Li, Y., Waas, A. M. & Arruda, E. M. The effects of the interphase and strain gradients on the elasticity of layer by layer (LBL) polymer/clay nanocomposites. Int. J. Solids Struct. 48, 1044–1053 (2011)

    CAS  Article  Google Scholar 

Download references


We acknowledge support from DARPA (grant HR0011-10-C-0192, MATLOG programme) and NextGen Aeronautics. We also acknowledge support from the NSF under grants ECS-0601345, CBET 0933384, CBET 0932823 and CBET 1036672. This work was also partially supported by the US Department of Defense under grant award no. MURI W911NF-12-1-0407. We thank the University of Michigan’s Electron Microscopy and Analysis Laboratory (EMAL) for assistance with electron microscopy, and the NSF for grants (numbers DMR-0320740 and DMR-9871177) funding the purchase of the JEOL 2010F analytical electron microscope used in this work. This work was supported by a National Research Foundation of Korea (NRF) grant (no. NRF-2015R1D1A1A01058029) funded by the Government of Korea (Ministry of Education). We also thank A. Jung for help with scanning electron microscopy.

Author information




N.A.K. and B.Y. conceived the project and designed the experiments. B.Y. and S.H.C. carried out the design and fabrication of the columnar composites and LBL films, and performed the mechanical testing experiments. T.S., A.M.W. and E.M.A. were responsible for the finite-element modelling data and assisted in the mechanical testing of the composites. N.L. was responsible for selecting the coarse grained model, and for performing molecular dynamics simulations and analysing the data. D.B. performed SEM imaging of the teeth. N.A.K., B.Y., T.S. and N.L. co-wrote the paper.

Corresponding author

Correspondence to Nicholas A. Kotov.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text and Data, Supplementary Figures 1-10, Supplementary Tables 1-2, Supplementary Comments 1-2 and additional references. (PDF 1289 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yeom, B., Sain, T., Lacevic, N. et al. Abiotic tooth enamel. Nature 543, 95–98 (2017).

Download citation


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing