Highlights

Semiconductor nanocrystals are sensitive to air and solvents, which hinders wet-chemical processing under ambient conditions. This problem has limited the scaling of nanocrystal device dimensions and large-scale device integration achievable by  conventional processing. We demonstrated a simple, in-situ recovery route using indium metal as a chemical agent which upon thermal activation is triggered to diffuse and repair the damage introduced by chemical and environmental exposure that degrade the electronic properties of semiconductor NC thin films and their devices.

The mechanical failure of amorphous systems is not well understood, but recent work by Liu and co-workers suggests that low-frequency vibrational modes are concentrated in localized regions, or “soft spots,” that are prone to rearrange. Yodh and Liu experimentally studied the nature of soft spots in crystalline and amorphous packings of colloidal spheres.  In crystals  [1], they found soft spots to be concentrated on topological defects such as grain boundaries and dislocations that are well known to serve as flow defects in crystals.

Dendrimers are highly branched molecules. Amphiphilic glycodendrimers have been synthesized for the first time. These macro-molecules have tunable carbohydrate head groups and hydrophobic tails. The precise architecture of the dendrimers facilitates assembly of precise structures, including vesicles (glycodendrimersomes). These novel vesicles display biological activity, including fusion and coalescence in response to lectins.

  The term “defect” suggests something to be avoided.  However, our team has developed an extensive toolkit to control the locations, shapes, and detailed geometry of so-called topological defects in liquid crystals, the same sorts of materials used in the $100bn/year display industry.  Our goal is to harness these defects to use them as cues for further directed- and self-assembly, as lenses and optical elements, and as building blocks for hierarchical materials.

Spin resonance in diamond using a MEMS resonator

Electron microscopy reveals the fundamental steps of bending An international team of Cornell researchers and collaborators was recently entered into the Guinness Book of World Records for fabricating the world’s thinnest pane of glass — only two atoms thick!

Addition of rubber particles to epoxy thermosets has been successful for toughening these brittle materials.

Using a series of acceptor-polymer-acceptor triads, IRG-2 investigators have measured intramolecular exciton diffusion in poly-3(hexylthiophene) (P3HT) for the first time.