Abstract
Nature has developed a wide range of design strategies to produce materials with remarkable properties, including for example the dazzling optical effects of butterfly wings and the self-cleaning ability of the lotus leaf. Taking a cue from Nature, where fabrication of structured materials follows a bottom-up approach, I will discuss synthesis and assembly of nanoparticles and their polymer nanocomposites for biomimetic color displays and omniphobicity. By controlling the solvent evaporation rate and surface wettability, we create quasi-amorphous photonic structures from colloidal nanoparticles, illustrating angle-independent, structural colors. The color can be tuned by the particle size, spacing, refractive index, and introduction of fluorescent dyes, while the color contrast can be enhanced using additives. By using nanoparticles of diameter less than 100 nm and control of particle surface chemistry, we create transparent films that repel water and oil on a wide range of substrates. I will discuss different assembly strategies, and the combination of self-assembly with inkjet printing and photolithography. Lastly, by coupling the materials-environment response at the nano- and microscales with CMOS technology, I will demonstrate a light intensity sensor with tunable color/transparency as the first step toward responsive building skins.
Background
Education
Ph.D., 1999, Cornell University ; M. S., 1997, Cornell University ; B.S. 1992, Fudan University
Positions Held
July 2013-present, Professor, Materials Science & Engineering, University of Pennsylvania
July 2009-June 2013, Associate Professor, Materials Science & Engineering, University of Pennsylvania
January 2004-June 2009, Skirkanich Chair of Innovation Assistant Professor, Materials Science & Engineering, and Chemical and Biomolecular Engineering, University of Pennsylvania
July 1999-December 2003, Member of Technical Staff, Department of Materials Research, Bell Laboratories, Lucent Technologies
Research Interests:
Developing biomimetic materials through novel materials synthesis and fabrication at the convergence of top-down and bottom-up approaches for directed assembly of complex, multi-functional structures from polymers, gels, biomaterials, and organicinorganic hybrids. By coupling of chemistry, fabrication and external stimuli, we
address the fundamental questions at surface-interface in a precisely controlled environment, and study the structure-property relationship. Special interests involve synthesis and engineering of well-defined polymers and
inorganic materials with controlled size, shape, and morphology over multiple length scales, study of their unique surface, optical, and mechanical properties, surface functionalization and dynamic tuning on topographic surfaces, biomimetic mineralization on functional polymer templates, directed-assembly of nano- and micro-objects (particles, rods) in solutions and on patterned surfaces, patterning and assembly of complex structures via harnessing elastic instability and curvature.
Honors/Distinctions
2012, Arthur K. Doolittle Award from the American Chemical Society, Division of Polymeric Materials Science and Engineering (PMSE) for the paper entitled "Understanding pattern transformation mechanisms in different responsive hydrogel membranes."
2011, Faculty mentor, Scientific Career Development at Gordon Research Seminar (GRS) on Adhesion Science
2011, Speaker at Japan-American Frontiers of Engineering Symposium (Japan). Invited by National Academy of Engineering
2011, Invited speaker, Youth Leadership Forum, The 12th Fudan University World Alumni Conference
2007, Participant of NSF Workshop in Polymers
2006, NSF/DMR CAREER award
2006-2008, 3M Non-tenured faculty award
2005-2011, LRSM IRG-1 Thrust co-leader, “Filamentous Networks & Structured Gels”
2004, TR100 (now TR 35) as one of the world’s top young innovators under age of 35 selected by MIT Technology Review
2004, ACS Presidential Award for IUPAC 40th Anniversary Symposium on Macromolecules
2004, Selected to German-American Frontiers of Engineering Symposium (Germany) by National Academy of Engineering
2003, Bell Labs team for the Technical Insights’ Excellence in Research Award on “Microfluidics in Photonics” selected by Frost and Sullivan
2002, Selected to Frontiers of Engineering Symposium by National Academy of Engineering as one of the top 100 young engineers
2001, Unilever Award in Polymer Science and Engineering from American Chemical Society
1999, ICI Award in Applied Polymer Science from American Chemical Society
Selective Publications
（1） Lee, S. and Yang, S.*, “Fabrication and Assembly of Magneto-Responsive,Anisotropic and Hybrid Microparticles of Variable Size and Shape”, Angew. Chem. Ed. Int. Accepted. 2013.
（2） Chen, C.-M., Chiang, C.-L., Lai, C.-L., Xie, T. and Yang, S.*, "Buckling-based strong dry adhesives via interlocking", Adv. Funct. Mater., 2013, ASAP.
（3） Honglawan, A. Beller, D. A. , Cavallaro, M. Jr., Kamien, R. D.*, Stebe, K. J. and Yang, S.*, “Topographically-induced hierarchical assembly and geometrical transformation of focal conic domain arrays in smectic liquid crystals”, Proc. Nat. Acad. Sci. USA, 2013, 110 (1), 34-39.
（4） Honglawan, A., Beller, D. A., Cavallaro, M., Kamien, R. D.*, Stebe, K. J. and Yang, S.*, “Pillar Assisted Epitaxial Assembly of Toric Focal Conic Domains of Smectic-A Liquid Crystals”, Adv. Mater., 2011, 23 (46), 5519-5523.
（5） Liang, G., Zhu, X., Xu, Y., Li, J. and Yang, S.*, “Holographic Design and Fabrication of Diamond Symmetry Photonic Crystals via Dual-beam Quadruple Exposure”, Adv. Mater. 2010, 22(40), 4524–4529.
（6） Yang, S.*, Khare, K., and Lin, P.-C. “Harnessing Surface Wrinkle Patterns in Soft Matter” Adv. Funct. Mater. 2010, 20 (16) 2550–2564.
（7） Chandra, D. and Yang, S.*, “Stability of high-aspect-ratio micropillar arrays against adhesive and capillary forces”, Acc. Chem. Res.2010 43 (8), 1080-1091
（8） Zhang, Y., Lin, C.-T., Yang, S.*, “Fabrication of Hierarchical Pillar Arrays from Thermoplastic and Photosensitive SU-8”, Small, 2010, 6(6) 768 – 775.
（9） McConnell, M. D., Kraeutler, M. J., Yang, S.* and Composto, R. J.*, “Patchy and Multiregion Janus Particles with Tunable Optical Properties”, Nano Lett., 2010, 10 (2), 603–609
（10） Moon, J.* and Yang, S.*, “Chemical Aspects of Three-dimensional Photonic Crystals”, Chem. Rev., 2010, 110 (1), pp 547–574.
（11） Xu, Y., Zhu, X and Yang, S.*, “Crack-free 3D hybrid microstructures from photosensitive organosilicates as versatile photonic templates”, ACS Nano, 2009, 3(10), 3251–3259.
（12） Guvendiren, M. Yang, S.*, and Burdick, J. A.*, “Swelling-Induced Surface Patterns in Hydrogels with Gradient Crosslinking Density”, Adv. Funct. Mater.2009, 19(19), 3038-3045.
（13） Guvendiren, M. Heiney, P. and Yang, S.*,“Precipitated calcium carbonate hybrid hydrogels: structural and mechanical properties”, Macromolecules, 2009, 42 (17),6606–6613.
（14） Zhang, Y., † Reed, J. C.,† and Yang, S.*, “Creating a Library of Complex Metallic Nanostructures via Harnessing Pattern Transformation of a Single PDMS Membrane”, ACS Nano, 2009, 3 (8), 2412–2418 (Cover). († : equal contribution)
（15） Kang, J.-H., Moon, J. H., Lee, S.-K., Park, S.-G., Jang, S. G., Yang, S., and Yang, S.-M.*, “Thermo-responsive hydrogel photonic crystals by three-dimensional holographic lithography”, Adv. Mater. 2008, 20, 3061-3065.
（16） Zhang, Y. Matsumoto, E. A., Peter, A., Lin, P., Kamien, R. D.*, and Yang, S.*, Tian, F., Wang, C.*, and Yang, S.*, “Water-driven morphological transitions nano-assemblies from amphiphilic random copolymers and their light-triggered dissociation”, Macromolecules, 2008, 41 (10), 3385-3388.
（17） “One-step nanoscale assembly of complex structures via harnessing of an elastic instability”, Nano Lett., 2008, 8 (4), 1192-1196.
（18） Moon, J. H., Kim, A. J., Crocker, J. C., and Yang, S.*, “High-throughput synthesis of anisotropic colloids via holographic lithography”, Adv. Mater. 2007, 19, 2520-2524.
（19） Moon, J. H., Xu, Y., Dan, Y., Yang, S.-M., Johnson, A. T. and Yang, S.*, “Triply periodic bicontinuous structures as templates for photonic crystals: a pinch-off problem”, Adv. Mater., 2007, 19 (11), 1510-1514.
（20） Qin, S., Geng, Y. Discher, D. E.*, and Yang, S.*, “Cold-controlled assembly and release of giant vesicles from poly(ethylene oxide-b-N-isopropylacrylamide)”, Adv. Mater., 2006, 18, 2905-2909.
（21） Yang, S.*; Chen, G; Megens, M.; Ullal, C. K.; Han, Y.-J.; Rapaport, R.; Thomas, E. L.; Aizenberg, J. “Functional biomimetic microlens arrays with integrated pores”, Adv. Mater. 2005, 17, 435.
（22） Yang, S.*; Krupenkin, T. N.; Mach, P. and Chandross, E. A. “Fabrication of tunable and latchable liquid microlens with photopolymerizable components” Adv. Mater. 2003, 15 (11), 940.
