Stabilized emulsions containing the oscillating Belousov - Zhabotinsky chemical reaction (BZ) show interesting dynamics. Each drop acts as an independent chemical clock. However, they chemically communicate and exhibit collective behavior. In (a) three photos of the same hexagonally packed 100 micron diameter BZ drops are shown 80 seconds apart. White corresponds to the oxidized state; black to reduced. The pattern is explained in (b); first all green drops are in the oxidized state, then all blue drops and finally all red drops.

fd virus is a polymeric virus 1 mm in length and 10 nm in diameter. We bind fluorescently labeled fd to 1 mm diameter polystyrene spheres creating a charged polymer stabilized colloid (hairy bead) and measure the interparticle potential using a double laser trap. We first measure the interaction energy of (a) bare beads and (b) then the hairy beads, seen here in fluorescence microscopy. (c) Electron micrograph of hairy beads. The repulsive energy of hairy beads is large when the beads are close.

A simple computational model demonstrates the assembly of self-limited filamentous bundles. The images are taken from dynamic Monte Carlo simulations in which chiral subunits spontaneously assemble under different interaction strengths and degrees of chirality. (a) Moderate interactions and moderate chirality reproducibly lead to a self-limited bundle with three layers of subunits, while stronger chirality (b) results in a self-limited two-layer bundle. (c) With strong interactions, frustration is relieved by defects, which enable the formation of branched networks and irregular bundles.

The plasmonic properties of noble metal nanoparticles have potential uses in a wide variety of technologies based on their optical response.Â’  Recent collaborative efforts of the NU-MRSEC demonstrate that correlated localized surface plasmon resonance (LSPR) spectroscopy and high-resolution transmission electron microscopy (HRTEM) measurements can be used to obtain the optical response and detailed structural information for a single nanoparticle.Â’  By carefully incorporating the HRTEM structural details into finite-difference time-domain (FDTD) electrodynamics calculations,

Made possible by a grant from the Connecticut Office of Workforce Competitiveness (OWC) the goal is to provide Connecticut's teachers with cutting edge imaging tools for their classrooms. A table top scanning electron microscope (mini-SEM) with elemental analysis capabilities was purchased. Typical SEMs are large and require extensive training and maintenance. Initially teachers at high schools and Connecticut's Community Technical Colleges (CTCs) are targeted for professional development and implementation.

Understanding the locations of atoms as they are deposited on a surface is critical for growing interfaces of electronicÂ’  device quality. One unique tool that is key to this endeavor, is the high-resolution, low-temperature ultrahigh vacuum scanning probe microscope for simultaneous operation in noncontact atomic force microscopy and scanning tunneling microscopy mode at 4 K available at CRISP (Yale). Download High resolution non-contact AFM Highlight

In an ordinary insulator, such as diamond, the occupied electronic states are separated from unoccupied states by a large energy “gap”. The gap prevents current flow when an electric field is applied. Recent research has uncovered a new class of insulators, called topological insulators, in which electrons can bypass the energy gap by moving in surface states. The energy vs. momentum dispersion of these unusual surface states are Dirac-like. They exhibit unusual topological properties which may be important for quantum computing.

Graphene is comprised of a single layer of C atoms in a hexagonal lattice array.  The electronic state of graphene is of great interest because the electron energy increases linearly with momentum, just like for photons and neutrinos.  This is called a massless, Dirac dispersion.  The nature of the electronic state at zero energy (the “Dirac point”) in a strong magnetic field H is currently the subject of theoretical debate.