This cover was designed by Dr. Jingwei Xie for an article published in ACS NANO (2009, 3, pp. 1151-1159). It shows neurites outgrowing from Dorsal Root Ganglia (DRG) on a two-dimensional mesh of electrospun nanofibers with orthogonal orientations. This research provides valuable information pertaining to the design of nanofiber-based scaffolds for neuroregenerative applications, as well as the effects of topology on neurite outgrowth, growth cone guidance, and axonal regeneration.
	This cover was designed by Dr. Byungkwon Lim for a major review article published in Angewandte Chemie International Edition (2009, 48, pp. 60-103). It illustrates the connections between atomic species (in the center) to metal nanocrystals with various shapes (the outer circle) through the seeds having different numbers of twin defects (the inner circle). Once the seed is fixed, the final shape displayed by the metal nanocrystal will be determined by the growth rates along different directions through the use of a capping agent.
	This cover was designed by Dr. Yujie Xiong for a communication published in Angewandte Chemie International Edition (2007, 46, pp. 790-794). It shows the roles of citrate or citric acid as a capping agent to preferentially bind to Pd{111} facets and to protect the highly twined Pd icosahedron from dissolution by shielding the oxygen from air -- a critical component for oxidative etching. As a result, Pd icosahedra could be obtained with a yield as high as 80%.
	This cover was designed by Professor Hong Yang at U. of Rochester for a special section on bionanotechnology published in Advanced Materials (2007, 19, p. 3085). This special section was co-edited by Professors Hong Yang and Younan Xia, and covers a broad range of subjects related to the synthesis of nanomaterials for biomedical applications (e.g., sensing, imaging, diagnosis, and treatment), as well as the use of biological principles in the design and fabrication of novel, improved nanomaterials (e.g., biomimetics).
	This cover was designed by Matthew Rycenga (Ph.D., 2006-2010) for a communication published in Advanced Materials (2008, 20, pp. 2416-2420). It shows the self-assembly of silver nanocubes (~100 nm in edge length) into dimers, chains, and three-dimensional crystal lattices. The self-assembly can be programmed and controlled by selectively modifying different faces of the nanocubes with a hydrophobic, alkanethiolate monolyer. For example, dimers formed when only one of the six faces is rendered hydrophobic.
	This cover was designed by Brian Mayer (Ph.D., 1999-2003) for a special issue published in Advanced Materials (2004, 16, p. 1245). The special issue was dedicated to Professor George M. Whitesides on the occasion of his 65th birthday. It includes an interview of Whitesides, 18 review articles, research news articles, and communications by his former students and postdoctoral fellow, with a focus on "soft lithography". It also contains a very useful essay by Whitesides on how to write a scientific paper (p. 1375).
	This cover was designed by Dr. Hiroshi Fudouzi (a visiting scientists from NIMS in Japan) for a communication published in Advanced Materials (2003, 15, pp. 892-896). It shows how to use colorless inks to print colorful images on photonic paper -- a composite material fabricated by infiltrating an opal lattice of polymer beads with an elastomer such as poly(dimethyl siloxane) (PDMS). When the PDMS matrix was swollen with a silicone fluid, the lattice constant and thus the wavelength of diffracted light increased.
	This cover was designed by Brian Mayer (Ph.D., 1999-2003) for a special issue on nanowires published in Advanced Materials (2004, 16, p. 1245). The special issue was co-edited by Professors Younan Xia and Peidong Yang. It includes 18 review articles, research news articles, and communications on the synthesis, chemistry, physics, and technological applications of metal and semiconductor nanowires. The review article by Xia, Yang, and their co-workers is the most cited paper published in Advanced Materials.
	This cover was designed by Byron Gates (the first Ph.D., 1999-2001) for a communication published in Advanced Materials (2000, 13, pp. 1605-1608). It shows the tuning of colors displayed by a photonic crystal with an external magnetic field. The photonic crystal was fabricated by co-self-assembly of polymer latex beads and superparamagnetic iron oxide nanoparticles. After solidification, the polymer beads were selectively removed, generating an inverse opal composed of the sintered iron oxide nanoparticles.
	This cover was designed by Yadong Yin (Ph.D., 1998-2002) for a communication published in Advanced Materials (2000, 12, pp. 1426-1430). It shows scanning electron micrograph of free-standing nanorings of single-crystal silicon that were fabricated by patterning silicon-on-insulator (SOI) wafer with phase-shifting, near-field optical lithography, followed by lift-off. This simple technique can also be extended to fabricate single-crystal silicon nanostructures with many different shapes or morphologies.
	This cover was designed by Brian Mayer (Ph.D., 1999-2003) for a communication published in Advanced Materials (2002, 14, pp. 279-282). It shows transmission electron micrograph of tellurium nanotubes at different stages of growth. The success of this synthesis is based upon the formation of a concentration depletion zone on the seed by controlling the reduction rate of a tellurium precursor. As such, tellurium atoms were preferentially added to the edges of the seed, leading to the formation of a nanotube.
	This cover was designed by Byron Gates (the first Ph.D., 1999-2001) for a special issue on photonic crystals published in Advanced Materials (1999, 13, p. 369). It shows scanning electron micrograph of an inverse opal of silica fabricated by infiltrating the voids in an opal lattice of polystyrene beads with a sol-gel precursor, followed by selective removal of the polystyrene beads by dissolution with an organic solvent. The special issue was edited by Professor Younan Xia and includes 23 articles from various groups.
	This cover was designed by Dr. Sang Hyun Park (the first postdoctoral fellow) and Byron Gates (the first Ph.D., 1999-2001) for a communication published in Advanced Materials (1999, 11, pp. 462-466). It shows scanning electron micrograph of three-dimensional lattice assembled from polystyrene beads in a fluidic cell (see the center for a photograph). Such a crystalline lattice is able to diffract light at a specific wavelength (as determined by the Bragg's law) and function as a photonic crystal with a pseudo band gap.
	This cover was designed by Yadong Yin (Ph.D., 1998-2002) for a feature article published in Advanced Functional Materials (2003, 13, pp. 907-918). It shows scanning electron micrograph of an array of colloidal clusters (or molecules) fabricated using template-assisted self-assembly (TASA). The key is to control the sizes of the templates (e.g., cylindrical holes patterned in a photoresist film) relative to the diameter of the polymer beads or other types of building blocks, which could be small as tens of nanometers.
	This cover was designed by Dr. Marta Ibisate (a visiting scientist from Spain who was supported by a Fulbright Fellowship) for an article published in Advanced Functional Materials (2006, 16, pp. 1627-1632). It shows scanning electron micrograph of dimers assembled from silica spheres. By controlling the interaction potential between colloidal spheres of silica , they could be induced to form dimers, which could be fixed by adding a sol-gel precursor to silica into the reaction system. The yield could be as high as 80%.
	This cover was designed by the editorial office for a special issue published in Advanced Materials (1999, 11, p. 1065). The special issue was co-edited by Professors Younan Xia and Rukang Li and was dedicated to all materials scientists in China, with a focus on "materials research in China: successes and problems". It includes 15 review articles, research news articles, and communications on a broad range of subjects related to materials science and engineering, as well as an essay on the funding mechanism and trend.
	This cover was designed by Yadong Yin (Ph.D., 1998-2002) for a feature article published in Australian Journal of Chemistry (2001, 54, pp. 287-290). It shows fluorescence optical micrograph of dimers assembled from polystyrene beads doped with two different organic dyes. The dimers were formed using a process developed by the Xia group and now known as template-assisted self-assembly (TASA). By choosing the right dimensions for the template, one can only place a specific number of polymer beads in each template.
	This cover was designed by Benjamin Wiley (Ph.D., 2002-2006) for a concepts article published in Chemistry: A European Journal (2006, 11, pp. 454-463). It illustrates the synthesis of silver nanocrystals with different shapes via the polyol process, which involves reduction of silver nitrate with ethylene glycol at an elevated temperature in the presence of poly(vinyl pyrrolidone) (PVP). By varying the experimental conditions, one can obtain silver nanocrystals with different shapes, including nanocubes and nanowires.
	This cover was designed by Dr. Yujie Xiong for a communication published in Journal of Materials Chemistry (2007, 17, pp. 2600-2602). It shows transmission electron micrograph (TEM) of silver nanoplates in the background and high-resolution TEM of the cross section of such a silver nanoplate, showing the stacking faults along the vertical direction. This synthesis is based upon the polyol reduction of silver nitrate in the presence of polyacrylamide, which can form complex with silver ions and thus slow down the reduction.
	This cover was designed by Jesse McCann (Ph.D., 2002-2006) for a feature article published in Journal of Materials Chemistry (2005, 15, pp. 735-738). It shows how the spinneret (see the center for a coaxial configuration) for electrospining can be modified to fabricate nanofibers with a wide range of different morphologies, including tubular fibers (upper left corner), porous fibers (upper right corner), and nanotubes with selectively functionalized inner or outer surface (lower corners).
	This cover was designed by Benjamin Wiley (Ph.D., 2002-2006) for a feature article published in the Journal of Physical Chemistry B (2006, 110, pp. 15666-15675). It shows the formation of silver nanocubes, pentagonal nanowires, and right bipyramids from atoms through three different types of seeds: single-crystal cubooctahedron, multiply twinned decahedron with a five-fold axis, and singly twinned, respectively. Such a shape control enables one to maneuver the optical (plasmonic) properties of silver nanocrystals.
	This cover was designed by Jingyi Chen (Ph.D., 2002-2006) for a feature article published in Langmuir (2007, 23, 4120-4129). It shows a scanning electron micrograph of platinum sea urchins -- aggregates of platinum nanoparticles whose surfaces are decorated with single-crystal platinum nanorods or nanowires. The key to the formation of platinum nanowires is to slow down the reduction of a platinum precursor via oxidative etching, by simply introducing ferric or ferrous species into the reaction system.
	This cover was designed by Yu Lu (Ph.D., 1999-2003) for an article published in Langmuir (2001, 17, pp. 6344-6350). It shows scanning electron micrograph of the cross section of a crystalline lattice self-assembled from polystyrene beads. This article describes a simple method based upon a fluidic cell for assembling polystyrene latex beads into three-dimensional opals with long-range order. The fluidic cell could be easily fabricated by sandwiching a gasket (cut from a Mylar film) between two glass slides.
	This cover was designed by Dr. Jingwei Xie for a review article published in Macromolelcular Rapid Communications (2008, 29, pp. 1775-1792). It shows the basic setup for electrospinning and the use of electrospun nanofibers for various biomedical applications, including their use as scaffolds for tissue engineering. For example, uniaxially aligned nanofibers can be utilized to manipulate the differentiation of stem cells, and to guide and enhance the outgrowth of neurites. Such abilities are highly sought in nerve repair.
	This cover was designed by Benjamin Wiley (Ph.D., 2002-2006) for a special issue published in Materials Research Society (MRS) Bulletin (2005, 30, p. 338). The special issue was co-edited by Professors Younan Xia and Naomi Halas, with a focus on the plasmonic properties of metal nanoparticles. It includes  six review articles on the synthesis and characterization of silver and gold nanostructures, as well as their surface plasmon resonance (SPR) properties and applications in sensing or surface-enhanced Raman scattering (SERS).
	This cover was designed Yu Lu (Ph.D., 1999-2003) for a paper published in Nano Letters (2002, 2, pp. 785-788). It shows scanning electron micrograph (in the back-scattering mode) of a crystalline lattice assembled from gold@silica core-shell colloidal spheres. Since gold has a higher atomic number than silicon, one can clearly see the gold cores even though they are enclosed in silica shells. Such core-shell particles offers a new class of building blocks for fabricating photonic crystals with additional plasmonic features.
	This cover was designed by Dr. Unyong Jeong for an article published in Nature Materials (2005, 4, pp. 671-675). It shows a colorized scanning electron micrograph of polystyrene beads with hollow interiors and controllable pores in their surfaces. This novel class of colloidal particles were fabricated by swelling solid polymer beads with a proper solvent, followed by freeze-drying. A combination of phase separation and solvent evaporation results in the formation such hollow, porous polymer beads useful in encapsulation.
	This cover was designed by Byron Gates (the first Ph.D., 1999-2001) for a news article published in Northwest Technology, a magazine that aims to feature new technological developments in the northwest region, mainly from the U. of Washington. It shows scanning electron micrograph of an opal lattice of polystyrene beads. In this article, it highlights some of the exciting research from Xia group related to the fabrication of photonic crystals from colloidal building blocks through a self-assembly approach.
	This cover was designed by Dr. Sung-Wook Choi for a paper published in Small (2009, 4, pp. 454-459). It shows optical micrographs of polymer beads with uniform sizes in the range of 30-300 mm that could be easily produced using a simple fluidic device constructed from a syringe needle, a glass capillary, and a PVC tube. The uniform polymer beads could be assembled into three-dimensional lattices and further utilized as templates to produce inverse opal scaffolds with uniform pore sizes for tissue engineering.