One of the challenges in developing robust multilayers is the need to predict the interfacial strength between hard and soft materials. For example, in the case of drug eluting stents that are being used increasingly to treat arteriosclerosis, there are concerns that the drug-eluting layer may detach from the polymeric layers that are used to attach the soft drug eluting layers to the hard metallic stent substrate.

A physical hypothesis based on theory and ab initio modeling for the stamping of graphene and few layers graphene (FLG) on silica is presented, and the feasibility of site-specific stamping of FLG patterns is demonstrated experimentally (figure below shows 10-layer FLG pattern stamped on silica). The site-specific nature of the patterned stamps over large areas could enable high-throughput fabrication of future graphene-based integrated devices.

Mr. Chin-Yi Liu, a graduate student working in Professor Kortshagen’s group, demonstrated the first hybrid solar cell based on silicon nanocrystals and a conductive polymer, poly-3(hexylthiophene) (P3HT). 

The UMN MRSEC has demonstrated the control of nanocrystal orientation within nanoporous polymer monoliths prepared from ABC triblock terpolymers containing a robust A block (polystyrene), a hydrophilic B block [poly(dimethylacrylamide)], and an etchable C block (polylactide) developed in the IRG.

MRSEC faculty members Paul Crowell, Chris Leighton, and Dan Dahlberg and their students guided 25 high school students through an exploration of magnetism and its applications to technology as part of the Institute of Technology Center for Education Programs (ITCEP) Exploring Careers in Science & Engineering summer camp. The day of activities included hands-on demos, a lunch with recent graduates working in industry, and an afternoon spent building motors, magnetic levitators, generators, and radios.

Self-assembling block copolymers provide a simple, efficient, and rapid way to generate nanoscale patterns over macroscopic areas:Â’  for example, an array of 20 nm dots covering a 100 mm silicon wafer.Â’  These dots can be "lined up" by applying shear to the block copolymer film [1], but the order is not perfect:Â’  dislocations (lines of dots that abruptly start or end) remain in the film.Â’  In a recent study [2], PCCM researchers have shown that the quality of orientational order of the dots depends only on the density of these dislocations; in the limit that dislocations are

Surface plasmons - collective oscillations of free charges - on metal surfaces have resulted in demonstrations of enhanced optical transmission, collimation of light through a subwavelength aperture, negative permeability and refraction at visible wavelengths, and second-harmonic generation. The structures that display these plasmonic phenomena typically consist of ordered arrays of particles or holes with sizes of the order of 100 nm.

Organic photovoltaic devices (OPVs) hold promise for a variety of applications requiring alternative energy generation. Through a collaboration betweenÂ’  Northwestern University MRSEC IRG 4 and Wright Patterson Air Force Base, a new strategy for characterizing the electrical and optical performance of operating OPVs has recently been developed. Atomic force photovoltaic microscopy allows the photocurrent response in OPVs and other optoelectronically-active materials and devices to be spatially mapped down to the nanometer length scale.