The creation of materials with a combination of high strength, substantial deformability and ductility, large elastic limit and low density represents a long-standing challenge, because these properties are, in general, mutually exclusive. Using a combination of two-photon lithography and high-temperature pyrolysis, we have created micro-sized pyrolytic carbon with a tensile strength of 1.60 ± 0.55 GPa, a compressive strength approaching the theoretical limit of ~13.7 GPa, a substantial elastic limit of 20–30% and a low density of ~1.4 g cm−3. This corresponds to a specific compressive strength of 9.79 GPa cm3 g−1, a value that surpasses that of nearly all existing structural materials. Pillars with diameters below 2.3 μm exhibit rubber-like behaviour and sustain a compressive strain of ~50% without catastrophic failure; larger ones exhibit brittle fracture at a strain of ~20%. Large-scale atomistic simulations reveal that this combination of beneficial mechanical properties is enabled by the local deformation of 1 nm curled graphene fragments within the pyrolytic carbon microstructure, the interactions among neighbouring fragments and the presence of covalent carbon–carbon bonds.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $15.58 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the plots and other findings of this study are available from the corresponding authors upon request.
Meyers, M. A. & Chawla, K. K. Mechanical Behavior of Materials (Cambridge Univ. Press, 2009).
Ashby, M. F. in Materials Selection in Mechanical Design 4th edn, Ch. 4, 57–96 (Butterworth-Heinemann, 2011).
Muth, J. T., Dixon, P. G., Woish, L., Gibson, L. J. & Lewis, J. A. Architected cellular ceramics with tailored stiffness via direct foam writing. Proc. Natl Acad. Sci. USA 114, 1832–1837 (2017).
Lucas, R., Meza, L. R., Das, S. & Greer, J. R. Strong, lightweight and recoverable three-dimensional ceramic nanolattices. Science 345, 1322–1326 (2014).
Wang, H. et al. Ultralight, scalable and high-temperature-resilient ceramic nanofiber sponges. Sci. Adv. 3, e1603170 (2017).
Lu, L., Shen, Y., Chen, X., Qian, L. & Lu, K. Ultrahigh strength and high electrical conductivity in copper. Science 304, 422–426 (2004).
Sanders, P. G., Eastman, J. A. & Weertman, J. R. Elastic and tensile behavior of nanocrystalline copper and palladium. Acta Mater. 45, 4019–4025 (1997).
Zhang, Y. et al. Microstructures and properties of high-entropy alloys. Prog. Mater. Sci. 61, 1–93 (2014).
Greer, J. R. & Hosson, J. T. Plasticity in small-sized metallic systems: intrinsic versus extrinsic size effect. Prog. Mater. Sci. 56, 654–724 (2011).
Wu, B., Heidelberg, A. & Boland, J. J. Mechanical properties of ultrahigh-strength gold nanowires. Nat. Mater. 4, 525–529 (2005).
Lowry, M. B. et al. Achieving the ideal strength in annealed molybdenum nanopillars. Acta Mater. 58, 5160–5167 (2010).
Gogotsi, Y. Not just graphene: the wonderful world of carbon and related nanomaterials. MRS Bull. 40, 1110–1121 (2015).
Lee, C., Wei, X., Kysar, J. W. & Hone, J. Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 321, 385–388 (2008).
Rasool, H. I., Ophus, C., Klug, W. S., Zettl, A. & Gimzewski, J. K. Measurement of the intrinsic strength of crystalline and polycrystalline graphene. Nat. Commun. 4, 2811 (2013).
Zhang, P. et al. Fracture toughness of graphene. Nat. Commun. 5, 3782 (2014).
Wei, Y. et al. The nature of strength enhancement and weakening by pentagon–heptagon defects in graphene. Nat. Mater. 11, 759–763 (2012).
Song, Z., Artyukhov, V. I., Wu, J., Yakobson, B. I. & Xu, Z. Defect-detriment to graphene strength is concealed by local probe: the topological and geometrical effects. ACS Nano 9, 401–408 (2015).
Cao, A., Dickrell, P. L., Sawyer, W. G., Ghasemi-Nejhad, M. N. & Ajayan, P. M. Super-compressible foam-like carbon nanotube films. Science 310, 1307–1310 (2005).
Qu, L., Dai, L., Stone, M., Xia, Z. & Wang, Z. L. Carbon nanotube arrays with strong shear binding-on and easy normal lifting-off. Science 322, 238–242 (2008).
Barg, S. et al. Mesoscale assembly of chemically modified graphene into complex cellular networks. Nat. Commun. 5, 4328 (2014).
Qin, Z., Jung, G. S., Kang, M. J. & Buehler, M. J. The mechanics and design of a lightweight three-dimensional graphene assembly. Sci. Adv. 3, e1601536 (2017).
Zhang, H., Lopez-Honorato, E. & Xiao, P. Fluidized bed chemical vapor deposition of pyrolytic carbon-III. Relationship between microstructure and mechanical properties. Carbon 91, 346–357 (2015).
Stein, I. Y. et al. Structure–mechanical property relations of non-graphitizing pyrolytic carbon synthesized at low temperatures. Carbon 117, 411–420 (2017).
Zhao, Z. et al. Nanoarchitectured materials composed of fullerene-like spheroids and disordered graphene layers with tunable mechanical properties. Nat. Commun. 6, 6212 (2015).
Hu, M. et al. Compressed glassy carbon: an ultrastrong and elastic interpenetrating graphene network. Sci. Adv. 3, e1603213 (2017).
Bauer, J., Schroer, A., Schwaiger, R. & Kraft, O. Approaching theoretical strength in glassy carbon nanolattices. Nat. Mater. 15, 438–443 (2016).
Li, X. & Gao, H. Mechanical metamaterials: smaller and stronger. Nat. Mater. 15, 373–374 (2016).
Harris, P. J. New perspectives on the structure of graphitic carbons. Crit. Rev. Solid State 30, 235–253 (2005).
Cançado, G. L. et al. General equation for the determination of the crystallite size of nanographite by Raman spectroscopy. Appl. Phys. Lett. 88, 163106 (2006).
Bruley, J., Williams, D. B., Cuomo, J. J. & Pappas, D. P. Quantitative near-edge structure analysis of diamond-like carbon in the electron microscope using a two-window method. J. Microsc. 180, 22–32 (1995).
Basu, B., Tiwari, D., Kundu, D. & Prasad, R. Is Weibull distribution the most appropriate statistical strength distribution for brittle materials? Ceram. Int. 35, 237–246 (2009).
Bazant, Z. P. & Xiang, Y. Size effect in compression fracture: splitting crack band propagation. J. Eng. Mech. 13, 162–172 (1997).
Zhao, J. X., Bradt, R. C. & Walker, P. L. The fracture toughness of glassy carbons at elevated temperatures. Carbon 23, 15–18 (1985).
Yajima, S., Hirai, T. & Hayase, T. Micro-hardness of pyrolytic graphite and siliconated pyrolytic graphite. Tanso 69, 41–47 (1972).
Oku, T., Kurumada, A., Imamura, Y. & Ishihara, M. Effects of ion irradiation on the hardness properties of graphites and C/C composites by indentation tests. J. Nucl. Mater. 381, 92–97 (2008).
Dikin, D. et al. Preparation and characterization of graphene oxide paper. Nature 448, 457–460 (2007).
Jang, D., Li, X., Gao, H. & Greer, J. R. Deformation mechanisms in nanotwinned metal nanopillars. Nat. Nanotechnol. 7, 594–601 (2012).
Greer, J. R., Oliver, W. C. & Nix, W. D. Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients. Acta Mater. 53, 1821–1830 (2005).
Fu, S. Y., Lauke, B., Mäder, E., Yue, C. Y. & Hu, X. Tensile properties of short-glass-fiber- and short-carbon-fiber-reinforced polypropylene composites. Compos. Part A 31, 1117–1125 (2000).
Dunlay, W. A., Tracy, C. A. & Perrone, P. J. A Proposed Uniaxial Compression Test for High Strength Ceramics (US Army, 1989).
Wheeler, J. M. et al. Approaching the limits of strength: measuring the uniaxial compressive strength of diamond at small scales. Nano Lett. 16, 812–816 (2016).
Xu, B. & Tian, Y. High pressure synthesis of nanotwinned ultrahard materials. Acta Phys. Sin. 66, 036201 (2017).
Lai, A., Du, Z., Gan, C. L. & Schuh, C. A. Shape memory and superelastic ceramics at small scales. Science 341, 1505–1508 (2013).
Dusoe, K. J. et al. Ultrahigh elastic strain energy storage in metal-oxide-infiltrated patterned hybrid polymer nanocomposites. Nano Lett. 17, 7416–7423 (2017).
Mayer, J., Giannuzzi, L. A., Kamino, T. & Michael, J. TEM sample preparation and FIB-induced damage. MRS Bull. 32, 400–407 (2007).
Ke, X. et al. TEM sample preparation by FIB for carbon nanotube interconnects. Ultramicroscopy 109, 1353–1359 (2009).
Schaffer, M., Schaffer, B. & Ramasse, Q. Sample preparation for atomic-resolution STEM at low voltages by FIB. Ultramicroscopy 114, 62–71 (2012).
Jennings, A. T. & Greer, J. R. Tensile deformation of electroplated copper nanopillars. Philos. Mag. 91, 1108–1120 (2011).
Sadezky, A., Muckenhuber, H., Grothe, H., Niessner, R. & Pöschl, U. Raman microspectroscopy of soot and related carbonaceous materials: spectral analysis and structural information. Carbon 43, 1731–1742 (2005).
Plimpton, S. Fast parallel algorithms for short-range molecular dynamics. J. Comp. Phys. 117, 1–19 (1995).
Stuart, S. J., Tutein, A. B. & Harrison, J. A. A reactive potential for hydrocarbons with intermolecular interactions. J. Chem. Phys. 112, 6472–6486 (2000).
Deringer, V. L. & Csanyi, G. Machine learning based interatomic potential for amorphous carbon. Phys. Rev. B 95, 094203 (2017).
X.L. acknowledges financial support from the National Natural Science Foundation of China (grants 11522218 and 11720101002) and the National Basic Research of China (grant 2015CB932500). H.G. acknowledges funding from the National Science Foundation (grant DMR-1709318). J.R.G. acknowledges financial support by the US Department of Energy, Office of Basic Energy Sciences (DOE-BES) under grant DE-SC0006599. A.V. acknowledges the financial support of the Resnick Sustainability Institute at Caltech. The authors thank G. R. Rossman for assistance with Raman spectroscopy measurements, J. Yao for help with SIMS measurements and K. Narita for assistance with density measurements of pyrolytic carbon.
The authors declare no competing interests.
Peer review information: Nature Nanotechnology thanks Maria Pantano, Ping Xiao and other anonymous reviewer(s) for their contribution to the peer review of this work.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary text 1–5 Supplementary Figs. 1–20 Supplementary Figs. 1–20 Supplementary Table 1 Supplementary Table 1
In situ compression of 2.25-μm-diameter PyC micropillar
In situ tension of 1.5-μm-diameter PyC micropillar
Atomistic simulation of uniaxial compression on a 20-nm-diameter PyC nanopillar
Atomistic simulation of uniaxial tension of a 20-nm-diameter PyC nanopillar