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Like liquids, solids can flow under applied shear stresses.  In crystalline solids, figuring out vulnerable regions where the material will break under stress is well-established—they are typically controlled by a population of defects in the crystal structure known as dislocations.  In disordered solids, however, defects are everywhere, making the task of identifying such vulnerable spots much more daunting.

First principles modeling demonstrates  that the efficiency of Multi-Exciton Generation (MEG) increases as quantum dot size decreases resolving a major controversy.  The results were highly visible. 

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.

In a photovoltaic cell, an incident photon creates an electron (black circle in top sketch) and a hole (open circle). For maximum efficiency, the opposite charges should be swept to opposite electrodes of the device (arrows) before they have a chance to recombine. The efficiency is further enhanced if a wide band gap organic semiconductor (e.g. P3HT) is grown on the surface of silicon.

Basic science concepts developed in IRG1 about jamming of granular materials enabled the development of a new class of soft robotic systems.  The image is of a jamming gripper which conforms to complex or fragile objects in the unjammed state, then hardens by jamming.  This work is a collaboration between the University of Chicago, the Cornell University Department of  Mechanical and Aerospace Engineering and iRobot Corp.

 The ability of an organic molecular solid to crystallize into different structures is  a phenomenon known as polymorphism.  Polymorphism is an issue of major concern in the pharmaceutical industry.  In many drug compounds, some fraction of the crystal structures that can be formed cause the drug to lose its therapeutic function.  If these structures are not known at the time of the drug’s release onto the market,