For many years now, MRSEC-affiliated faculty have accepted high school students into their labs during the summer, or on weekends during the semester, to undertake research projects that are supervised by a post-doctoral scholar or a senior graduate student. Student selection is made by the faculty member, who is responsible for the student during the program, and students first undertake safety training with EHRS. The number of students chosen for this program has been increasing: 10 in 2013, 17 in 2014, 16 in 2015, 19 in 2016.

Measuring correlated dynamics in molecular glasses:  Properties of molecular glasses change as they are made into nanometer sized films. Fakhraai and Riggleman showed that when the film thickness is reduced below 30 nm, the solid glass films become liquid-like and flow. This results in dewetting as shown in the figure.

The ‘micro-origami’ approach to making microrobotic devices is to form thin films that can fold themselves into desired, dynamically  transformable  shapes.

Nanocrystal “molecules” or “oligomers”: precise-number assemblies of nanocrystals  with well-defined geometrical arrangements. IRG-4 self-assembles, models, and measures these plasmonic metal nanocrystal oligomers in order to tailor their optical properties. The progression of the optical response with increasing oligomer size maps the evolution of the collective interactions within the structure. Applications may include decorating surfaces with these assemblies to form “metasurfaces” having engineerable interaction with light.  

Penn-COMPASS Partnership: IRG4/Solvay/CNRS IRG-4 creates new forms of matter by assembling nanometer-sized crystals into large, ordered, complex assemblies (nanocrystal superlattices.  Murray (IRG-4) and Donnio (CNRS) have synthesized a library of molecules (polycatenars) that enable new kinds of nanocrystals and superlattices. Broader Impact Lego Optics Lab @GEMS Summer Camp The Kagan (IRG-4) group created a Lego Optics lab for Penn’s Girls in Engineering, Math and Science (GEMS) summer camp for 6th-8th grade girls.

Disordered packings like sand piles and metallic glasses have arrangements of their constituent particles that appear very similar to those of a liquid.  It is a very hard and long-standing problem to be able “look” at the particle arrangement and tell if the the system is rigid, and where flow will initiate if the system is deformed.

At the smallest length scales, disordered systems such as nanoparticle packings and glass resemble the grains of sand on a beach. Lacking a structure, it is very difficult to understand how they deform and flow. We use a technique called atomic force microscopy, in which a sharp probe “feels” and pokes at a sample to measure its shape and mechanical properties. We are able to investigate at the length scale of a single particle.

Hybrid cell-like vesicles were prepared by coassembling (glyco)dendrimersomes with bacterial membrane vesicles (BMVs) derived from E. Coli. These assemblies incorporated transmembrane proteins such as the small fusion protein MgrB tagged with a red fluorescent protein, and glycoconjugates such as lipopolysaccharides and glycoproteins from E. Coli. In future work, coassembly of (glyco)dendrimersomes with mammalian including human cell membranes will be a focus with the goal of developing new systems for biomedical application. Broader Impact

Building complex three-dimensional (3D) materials from pre-programmed two-dimensional films presents exciting challenges and opportunities. To achieve this goal, researchers inspired by the paper folding techniques of origami and kirigami have successfully utilized the mechanical instabilities of thin films, such as buckling.

Probing and manipulating electronic band structures of 2D materials.