Recent physics research shows how spin-orbit coupling can rearrange electronic bands in a solid to make a "topological insulator" a new quantum phase of matter that is guaranteed to have conductive surfaces even though its bulk is insulating. What happens if you take a topological insulator and compress or expand it? A team of researchers at the University of Pennsylvania has examined this question. They find that if you expand the material enough, you can manipulate the Dirac

In 2008 The Penn MRSEC assisted a high school science teacher, Schuyler Patton, to prepare a year-long elective course on materials science for his high school, Central HS, Philadelphia. It started with one class of 33 students and it was very successful. In 2010-11, it was expanded to two sections with 66 students. In summer 2010, the Penn MRSEC offered a series of three hands-on workshops for teachers based on the laboratory experiments used in this course. The themes of these workshops were a)

In conjunction with the NOVA TV science program, the Penn MRSEC collaborated with Penn and Drexel University Materials Science Departments to arrange the first Philly Materials Science & Engineering Day on Feb. 5, 2011, which introduced the general public in the Philadelphia region to the world of materials. An extensive program was arranged that included demonstrations from many LRSM graduate research

The topological insulating materials offer conductive surface states that can be useful for quantum computing, catalysis, and other applications. In this recent work, we (Young, Chowdhury, Walter, Mele, Kane, and Rappe, under review, 2011) show that compressing the material strengthens the topological insulating state, while expanding the material eventually takes this behavior away completely. Using external pressure as a control parameter suggests general ways to strengthen this important physical effect.

Protein assembly at the air-water interface (AWI) occurs naturally in many biological processes, and provides a method for creating ordered biomaterials. However, the factors that control protein self-assembly at the AWI are generally not well understood. Here, we describe the behavior of a model protein, human serum albumin minimally labeled with Texas Red dye (HSA-TR), using a new confocal microscopy technique (Figure 1). Albumin was observed to form well-ordered, mesoscale

The objective of this Seed is to understand cooperative electronic, optical and electromagnetic phenomena emerging from the interactions of nanoscale building blocks. Recent work encompasses synthesis of nanoparticles (figure right) and nanowires, and the investigation of how nanocrystals can drive geometrical rearrangement in polymersome micelles (figure right). A second breakthrough (figure below), developed a ligand exchange process that enables flexible electronic devices (FETs) based on nanocrystal assemblies

Pioneering experiments reported [upper left] the ability of ferroelectric domain orientation to switch surface chemistry on and off, finding unambiguous evidence that the polarity of a ferroelectric surface can have a strong impact on the energetics of physisorption.

We have developed analytic methods that establish molecular constraints to photochemical efficiency in the engineering and construction of molecular photochemical materials and devices useful to addressing the global energy challenge. The absence, to-date, of analytic procedures has seriously handicapped progress in the development of photochemical devices. The new methods will provide important precise engineering guidelines to photochemical device construction in the future.

We have designed specialized protein molecules that organize around carbon nanotubes into an atomistically-predefined pattern. Targeted design of such self-organization is a powerful tool for engineering at the nano scale. For example, we have shown that our protein/nanotube hybrid can be used to generate a regularly-spaced array of gold nano-particle. Shown here is an exciting new concept we are currently pursuing. We believe that our nanotube/protein complexes can be used to

Design & engineering of modern devices increasingly requires complex nano- and micro-structures. One area of research now showing promise for creating such structures through simple solution techniques