diffusional rewelding of the damage, thus pro-viding the ultimate biomimetic property ofself healing.Thermodynamic compatibility of thepair of two-phase alloys requires a four-phase equilibrium at operating temperaturesand a two-phase equilibrium during solu-tion treatment. A preliminary thermody-namic feasibility analysis, including assess-ment of memory alloy stability require-ments, was performed by a team of juniorsin materials design class. Continued evalu-ation (38) has included a test of mechanicalconcepts that uses a TiNi-reinforced Snalloy composite prototype to demonstrateboth macroscopic strain reversal and thedesired crack-clamping behavior (41). Pre-cise multicomponent phase relations for theFe-based system have been evaluated withdiffusion couple experiments, and prototypesteel composites are being fabricated.The success of these initial designs sug-gests that the integration of computationalmaterials science within a systems engineer-ing framework offers a powerful new ap-proach for the creation of superior materialsthat have sophisticated control of a multi-level dynamic structure, combined with re-duced time and cost of materials develop-ment. These first steps herald a new synergyof the science and engineering of materials.REFERENCES AND NOTES___________________________1. G. B. Olson, M. Azrin, E. S. Wright, Eds., Innovationsin Ultrahigh-Strength Steel Technology [GovernmentPrinting Office (GPO), Washington, DC, 1990].2. C. S. Smith, A Search for Structure (MIT Press, Cam-bridge, MA, 1981).3.iiii,inMartensite, G. B. Olson and W. S. Owen,Eds. (ASM International, Materials Park, OH, 1992),pp. 21–39.4. C. Zener, Elasticity and Anelasticity of Metals (Univ.of Chicago Press, Chicago, IL, 1948).5. M. Cohen, Mat. Sci. Eng. 25, 3 (1976).6.G. B. Olson, in M. E. Fine Symposium, P. K. Liaw, J. R.Weertman, H. L. Markus, J. S. Santner, Eds. ( The Min-erals, Metals & Materials Society (TMS) of the AmericanInstitute of Mining, Metallurgical, and Petroleum Engi-neers (AIME), Warrendale, PA, 1991), p. 41.7. G. M. Jenkins, in Systems Behaviour, J. Beishon andG. Peters, Eds. (Harper and Row, London, for OpenUniv. Press, 1972), pp. 56–82.8. M. F. Ashby, Materials Selection in Mechanical De-sign (Pergamon, Tarrytown, NY, 1992).9. COSMAT Summary Report, Materials and Man’sNeeds (National Academy of Sciences, NationalAcademy Press, Washington, DC, 1974); MaterialsScience and Engineering for the 1990s (National Re-search Council, National Academy Press, Washing-ton, DC, 1989).10. N. P. Suh, The Principles of Design (Oxford Univ.Press, New York, 1990); L. D. Albano and N. P. Suh,Res. Eng. Des. 4, 171 (1992).11.B. Sundman, B. Jansson, J. O. Andersson, CALPHAD9, 153 (1985).12. G. Ghosh and G. B. Olson, Acta Metall. Mater. 42,3361 (1994).13.G. R. Speich, in Innovations in Ultrahigh-Strength SteelTechnology, G. B. Olson, M. Azrin, E. S. Wright, Eds.(GPO, Washington, DC, 1990), pp. 89–111.14. K. C. King, P. W. Voorhees, G. B. Olson, Metall.Trans. 22A, 2199 (1991).15. A. J. Allen, D. Gavillet, J. R. Weertman, Acta Metall.41, 1869 (1993).16. G. B. Olson, T. J. Kinkus, J. S. Montgomery, Surf.Sci. 246, 238 (1991).17. A. Umantsev and G. B. Olson, Scr. Metall. 29, 1135(1993).18. J. G. Cowie, M. Azrin, G. B. Olson, Metall. Trans. A2A, 143 (1989).19. A. Needleman, in Innovations in Ultrahigh-StrengthSteel Technology, G. B. Olson, M. Azrin, E. S.Wright, Eds. (GPO, Washington, DC, 1990), pp.331–346.20. Y. Huang and J. W. Hutchinson, in Modelling ofMaterial Behavior & Design, J. D. Embury, Ed. ( TMS-AIME, Warrendale, PA, 1990), pp. 129–148.21. M. J. Gore, G. B. Olson, M. Cohen, in Innovations inUltrahigh-Strength Steel Technology, G. B. Olson,M. Azrin, E. S. Wright, Eds. (GPO, Washington, DC,1990), pp. 425–441.22. G. B. Olson, J. Phys. V, Colloque C1, 407 (1996).23. R. G. Stringfellow, D. M. Parks, G. B. Olson, ActaMetall. 40, 1703 (1992).24. S. Socrate, thesis, Massachusetts Institute of Tech-nology (1996).25. C. J. Kuehmann, J. Cho, T. A. Stephenson, G. B.Olson, in Metallic Materials for Lightweight Applica-tions, E. B. Kula and M. G. H. Wells, Eds. (GPO,Washington, DC, 1994), pp. 337–355.26. C. J. McMahon Jr., in Innovations in Ultrahigh-Strength Steel Technology, G. B. Olson, M. Azrin,E. S. Wright, Eds. (GPO, Washington, DC, 1990), pp.597–618.27. J. R. Rice and J.-S. Wang, Mater. Sci. Eng. A 107,23 (1989).28. R. Wu, A. J. Freeman, G. B. Olson, Science 265, 376(1994).29.iiii, Phys. Rev. B 53, 7504 (1996).30. L. Zhong, R. Wu, A. J. Freeman, G. B. Olson, ibid.55, 11 135 (1997).31.iiii, unpublished results32. P. M. Anderson, J. S. Wang, J. R. Rice, in Innova-tions in Ultrahigh-Strength Steel Technology,G.B.Olson, M. Azrin, E. S. Wright, Eds. (GPO, Washing-ton, DC, 1990), pp. 619–649.33. J. F. Watton, G. B. Olson, M. Cohen, in Innovationsin Ultrahigh-Strength Steel Technology, G. B. Olson,M. Azrin, E. S. Wright, Eds. (GPO, Washington, DC,1990), pp. 705–737.34. G. Ghosh and G. B. Olson, in Proceedings of 51stAnnual Meeting of the Microscopy Society of Amer-ica, G. W. Bailey and C. L Rieder, Eds. (San Fran-cisco Press, San Francisco, CA, 1993).35. T. A. Stephenson, C. E. Campbell, G. B. Olson, Ad-vanced Earth-to-Orbit Propulsion Technology 1992,R. J. Richmond and S. T. Wu, Eds., NASA Conf.Publ. 3174 (1992), vol. 2, pp. 299–307.36. J. Wise, unpublished results.37. G. B. Olson and H. Hartman, J. Physique 43,C4–855 (1982).38. B. Files, thesis, Northwestern University (1997).39. G. B. Olson, K. C. Hsieh, H. K. D. H. Bhadeshia, inMicrostructures LCS ’94 (Iron and Steel Institute ofJapan, Tokyo, 1994).40. The Northwestern component of the SRG programhas been sponsored by the Office of Naval Re-search, the Army Research Office, NSF, NASA, theU.S. Department of Energy, the Electric Power Re-search Institute, and the Air Force Office of ScientificResearch, with industry gifts and fellowship support.Molecular Manipulation ofMicrostructures: Biomaterials,Ceramics, and SemiconductorsSamuel I. Stupp* and Paul V. BraunOrganic molecules can alter inorganic microstructures, offering a very powerful tool forthe design of novel materials. In biological systems, this tool is often used to createmicrostructures in which the organic manipulators are a minority component. Threegroups of materials—biomaterials, ceramics, and semiconductors—have been select-ed to illustrate this concept as used by nature and by synthetic laboratories exploringits potential in materials technology. In some of