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.

Self-healing materials with microvascular networks


Self-healing polymers composed of microencapsulated healing agents exhibit remarkable mechanical performance and regenerative ability1,2,3, but are limited to autonomic repair of a single damage event in a given location. Self-healing is triggered by crack-induced rupture of the embedded capsules; thus, once a localized region is depleted of healing agent, further repair is precluded. Re-mendable polymers4,5 can achieve multiple healing cycles, but require external intervention in the form of heat treatment and applied pressure. Here, we report a self-healing system capable of autonomously repairing repeated damage events. Our bio-inspired coating–substrate design delivers healing agent to cracks in a polymer coating via a three-dimensional microvascular network6 embedded in the substrate. Crack damage in the epoxy coating is healed repeatedly. This approach opens new avenues for continuous delivery of healing agents for self-repair as well as other active species for additional functionality.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Self-healing materials with 3D microvascular networks.
Figure 2: Mechanical behaviour and healing efficiency.
Figure 3: Grubbs’ catalyst effects on healing efficiency.

Similar content being viewed by others


  1. White, S. R. et al. Autonomic healing of polymer composites. Nature 409, 794–797 (2001).

    Article  CAS  Google Scholar 

  2. Brown, E. N., Sottos, N. R. & White, S. R. Fracture testing of a self healing polymer composite. Exp. Mech. 42, 372–379 (2002).

    Article  CAS  Google Scholar 

  3. Brown, E. N., White, S. R. & Sottos, N. R. Retardation and repair of fatigue cracks in a microcapsule toughened epoxy composite—part II: In situ self-healing. Compos. Sci. Technol. 65, 2474–2480 (2005).

    Article  CAS  Google Scholar 

  4. Chen, X. et al. A thermally re-mendable cross-linked polymeric material. Science 295, 1698–1702 (2002).

    Article  CAS  Google Scholar 

  5. Chen, X., Wudl, F., Mal, A. K., Shen, H. & Nutt, S. R. New thermally remendable highly cross-linked polymeric materials. Macromolecules 36, 1802–1807 (2003).

    Article  CAS  Google Scholar 

  6. Therriault, D., White, S. R. & Lewis, J. A. Chaotic mixing in three-dimensional microvascular networks fabricated by direct-write assembly. Nature Mater. 2, 265–271 (2003).

    Article  CAS  Google Scholar 

  7. Runyon, M. K., Johnson-Kerner, B. L. & Ismagilov, R. F. Minimal functional models of hemostasis in a biomimetic microfluidic system. Angew. Chem. Int. Edn 43, 1531–1536 (2004).

    Article  CAS  Google Scholar 

  8. Stroock, A. D. & Cabodi, M. Microfluidic biomaterials. Mater. Res. Soc. Bull. 31, 114–119 (2006).

    Article  CAS  Google Scholar 

  9. Lim, D., Kamotani, Y., Cho, B., Mazumder, J. & Takayama, S. Fabrication of microfluidic mixers and artificial vasculartures using a high-brightness diode-pumped Nd:YAG laser direct write method. Lab Chip 3, 318–323 (2003).

    Article  CAS  Google Scholar 

  10. Martin, P. Wound healing—Aiming for perfect skin regeneration. Science 276, 75–81 (1997).

    Article  CAS  Google Scholar 

  11. Nagaya, K., Ikai, S., Chiba, M. & Chao, X. Tire with self-repairing mechanism. JSME Int. J. 49, 379–384 (2006).

    Article  Google Scholar 

  12. Sonntag, P. et al. Biocide squirting from an elastomeric tri-layer film. Nature Mater. 3, 311–315 (2004).

    Article  CAS  Google Scholar 

  13. Kessler, M. R., Sottos, N. R. & White, S. R. Self-healing structural composite materials. Compos. Part. A 34, 743–753 (2003).

    Article  Google Scholar 

  14. Brown, E. N., White, S. R. & Sottos, N. R. Microcapsule induced toughening in a self-healing polymer composite. J. Mater. Sci. 39, 1703–1710 (2004).

    Article  CAS  Google Scholar 

  15. Brown, E. N., White, S. R. & Sottos, N. R. Retardation and repair of fatigue cracks in a microcapsule toughened epoxy composite—part I: Manual infiltration. Compos. Sci. Technol. 65, 2466–2473 (2005).

    Article  CAS  Google Scholar 

  16. Jones, A. S., Rule, J. D., Moore, J. S., White, S. R. & Sottos, N. R. Catalyst morphology and dissolution kinetics for self-healing polymers. Chem. Mater. 18, 1312–1317 (2005).

    Article  Google Scholar 

  17. Therriault, D. Directed Assembly of Three-Dimensional Microvascular Networks. Thesis, Univ. of Illinois at Urbana-Champaign (2003).

  18. Rule, J., Brown, E. N., Sottos, N. R., White, S. R. & Moore, J. S. Wax-protected catalyst microspheres for efficient self-healing materials. Adv. Mater. 72, 205–208 (2005).

    Article  Google Scholar 

  19. Bond, I. & Pang, J. ‘Bleeding composites’—enhanced damage detection and self repair using a biomimetic approach. Compos. Part. A 36, 183–188 (2005).

    Google Scholar 

  20. Schwab, P., Grubbs, R. H. & Ziller, J. W. Synthesis and applications of RuCl2(=CHR′)(PR3)2: The influence of the alkylidene moiety on metathesis activity. J. Am. Chem. Soc. 118, 100–110 (1996).

    Article  CAS  Google Scholar 

  21. Kim, S.-R. & Nairn, J. A. Fracture mechanics analysis of coating/substrate systems part I: Analysis of tensile and bending experiments. Eng. Fract. Mech. 65, 573–593 (2000).

    Article  Google Scholar 

  22. Kim, S.-R. & Nairn, J. A. Fracture mechanics analysis of coating/substrate systems part II: Experiments in bending. Eng. Fract. Mech. 65, 595–607 (2000).

    Article  Google Scholar 

  23. Nairn, J. A. & Kim, S.-R. A fracture mechanics analysis of multiple cracking in coatings. Eng. Fract. Mech. 42, 195–208 (1992).

    Article  Google Scholar 

Download references


This work has been financially supported by the Air Force Office of Scientific Research Multidisciplinary University Research Initiative (grant number F49550-05-1-0346). K.S.T. is supported in part by the Beckman Institute for Advanced Science and Technology Graduate Fellows Program. We extend our gratitude to the Imaging Technology Group at the Beckman Institute, especially S. Robinson, for assistance with scanning electron microscopy.

Author information

Authors and Affiliations



K.S.T. carried out all of the experiments and analysis. N.R.S. and S.R.W. conceived the microvascular substrate–coating experiment and directed the research. J.A.L. and S.R.W. developed the direct-write manufacturing method. J.S.M. assisted with the healing chemistry. All authors participated in discussions of the research and wrote the manuscript.

Corresponding author

Correspondence to Nancy R. Sottos.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary information, scheme 1 and figures S1-S3 (PDF 277 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Toohey, K., Sottos, N., Lewis, J. et al. Self-healing materials with microvascular networks. Nature Mater 6, 581–585 (2007).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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