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.

Surface-chemistry-driven actuation in nanoporous gold


Although actuation in biological systems is exclusively powered by chemical energy, this concept has not been realized in man-made actuator technologies, as these rely on generating heat or electricity first1. Here, we demonstrate that surface-chemistry-driven actuation can be realized in high-surface-area materials such as nanoporous gold. For example, we achieve reversible strain amplitudes of the order of a few tenths of a per cent by alternating exposure of nanoporous Au to ozone and carbon monoxide. The effect can be explained by adsorbate-induced changes of the surface stress2, and can be used to convert chemical energy directly into a mechanical response, thus opening the door to surface-chemistry-driven actuator and sensor technologies.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Illustration of surface-chemistry-driven actuation in nanoporous gold.
Figure 2: Performance of a surface-chemistry-driven nanoporous Au actuator.
Figure 3: Surface-stress-induced relaxation of Au nanostructures studied by fully atomistic molecular dynamics simulations.


  1. Ebron, V. H. et al. Fuel-powered artificial muscles. Science 311, 1580–1583 (2006).

    Article  CAS  Google Scholar 

  2. Ibach, H. The role of surface stress in reconstruction, epitaxial growth and stabilization of mesoscopic structures. Surf. Sci. Rep. 29, 193–263 (1997).

    Article  CAS  Google Scholar 

  3. Baughman, R. H. Playing nature’s game with artificial muscles. Science 308, 63–65 (2005).

    Article  CAS  Google Scholar 

  4. Weissmüller, J. et al. Charge-induced reversible strain in a metal. Science 300, 312–315 (2003).

    Article  Google Scholar 

  5. Mirfakhrai, T., Madden, J. D. W. & Baughman, R. H. Polymer artificial muscles. Mater. Today 10, 30–38 (2007).

    Article  CAS  Google Scholar 

  6. Kramer, D., Viswanath, R. N. & Weissmüller, J. Surface-stress induced macroscopic bending of nanoporous gold cantilevers. Nano Lett. 4, 793–796 (2004).

    Article  CAS  Google Scholar 

  7. Viswanath, R. N., Kramer, D. & Weissmüller, J. Adsorbate effects on the surface stress-charge response of platinum electrodes. Electrochim. Acta 53, 2757–2767 (2008).

    Article  CAS  Google Scholar 

  8. Haiss, W. Surface stress of clean and adsorbate-covered solids. Rep. Prog. Phys. 64, 591–648 (2001).

    Article  CAS  Google Scholar 

  9. Feibelman, P. J. First-principles calculations of stress induced by gas adsorption on Pt(111). Phys. Rev. B 56, 2175–2182 (1997).

    Article  CAS  Google Scholar 

  10. Kim, J., Samano, E. & Koel, B. E. Oxygen adsorption and oxidation reactions on Au(211) surfaces: Exposures using O2 at high pressures and ozone (O3) in UHV. Surf. Sci. 600, 4622–4632 (2006).

    Article  CAS  Google Scholar 

  11. Zielasek, V. et al. Gold catalysts: Nanoporous gold foams. Angew. Chem. Int. Ed. 45, 8241–8244 (2006).

    Article  CAS  Google Scholar 

  12. Biener, M. M., Biener, J. & Friend, C. M. Enhanced transient reactivity of an O-sputtered Au(111) surface. Surf. Sci. 590, L259–L265 (2005).

    Article  CAS  Google Scholar 

  13. Erlebacher, J. et al. Evolution of nanoporosity in dealloying. Nature 410, 450–453 (2001).

    Article  CAS  Google Scholar 

  14. Biener, J. et al. Size effects on the mechanical behavior of nanoporous Au. Nano Lett. 6, 2379–2382 (2006).

    Article  CAS  Google Scholar 

  15. van Bokhoven, J. A. et al. Activation of oxygen on gold/alumina catalysts: In situ high-energy-resolution fluorescence and time-resolved X-ray spectroscopy. Angew. Chem. Int. Ed. 45, 4651–4654 (2006).

    Article  CAS  Google Scholar 

  16. Newman, R. C. et al. Alloy corrosion. MRS Bull. 24, 24–28 (1999).

    Article  CAS  Google Scholar 

  17. Cattarin, S., Kramer, D., Lui, A. & Musiani, M. M. Preparation and characterization of gold nanostructures of controlled dimension by electrochemical techniques. J. Phys. Chem. C 111, 12643–12649 (2007).

    Article  CAS  Google Scholar 

  18. Yim, W. L. et al. Universal phenomena of CO adsorption on gold surfaces with low-coordinated sites. J. Phys. Chem. C 111, 445–451 (2007).

    Article  CAS  Google Scholar 

  19. Hodge, A. M. et al. Scaling equation for yield strength of nanoporous open-cell foams. Acta Mater. 55, 1343–1349 (2007).

    Article  CAS  Google Scholar 

  20. Weissmüller, J. & Cahn, J. W. Mean stresses in microstructures due to interface stresses: A generalization of a capillary equation for solids. Acta Mater. 45, 1899–1906 (1997).

    Article  Google Scholar 

  21. Viswanath, R. N., Kramer, D. & Weissmüller, J. Variation of the surface stress-charge coefficient of platinum with electrolyte concentration. Langmuir 21, 4604–4609 (2005).

    Article  CAS  Google Scholar 

  22. Zepeda-Ruiz, L. A. et al. Mechanical response of freestanding Au nanopillars under compression. Appl. Phys. Lett. 91, 101907 (2007).

    Article  Google Scholar 

  23. Diao, J. K., Gall, K. & Dunn, M. L. Atomistic simulation of the structure and elastic properties of gold nanowires. J. Mech. Phys. Solids 52, 1935–1962 (2004).

    Article  CAS  Google Scholar 

  24. Fiorentini, V., Methfessel, M. & Scheffler, M. Reconstruction mechanism of fcc transition-metal (001) surfaces. Phys. Rev. Lett. 71, 1051–1054 (1993).

    Article  CAS  Google Scholar 

  25. Torres, D., Neyman, K. M. & Illas, F. Oxygen atoms on the (111) surface of coinage metals: On the chemical state of the adsorbate. Chem. Phys. Lett. 429, 86–90 (2006).

    Article  CAS  Google Scholar 

  26. Umeno, Y. et al. Ab initio study of surface stress response to charging. EPL 78, 13001 (2007).

    Article  Google Scholar 

  27. Min, B. K. et al. Efficient CO oxidation at low temperature on Au(111). J. Phys. Chem. B 110, 19833–19838 (2006).

    Article  CAS  Google Scholar 

Download references


Part of this work was carried out under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. The authors want to express special thanks to F. F. Abraham (LLNL) and M. Duchaineau (LLNL) for generating the nanoporous Au samples for the molecular dynamics simulations.

Author information

Authors and Affiliations


Corresponding author

Correspondence to J. Biener.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Biener, J., Wittstock, A., Zepeda-Ruiz, L. et al. Surface-chemistry-driven actuation in nanoporous gold. Nature Mater 8, 47–51 (2009).

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