Millennium Café

The foundations of crystal chemistry were developed in the early 1900s when scientists realized that a combination of factors including atomic/ionic radii, electronegativity difference, and preferred valence could be used with incredible success to understand and predict an enormous spectrum of crystalline solids. For 100 years, the materials community depended on this approach to guide material engineering efforts. This presentation introduces the concept of entropic stabilization, an orthogonal approach to materials design, where one uses configurational entropy to stabilize new crystals that “escape” conventional predictive power. We will demonstrate the ability to incorporate metal cations into “unusual” structural environments, and potentially realize new materials with interesting structures and physical properties.

Fluid turbulence is everywhere in the natural and engineered world: a complex tangle of vortices and eddies that span a wide range of length and time scales. However, from the point of view of objects and animals suspended in turbulence, this complexity is highly dependent on scale. Small, nearly-massless things are passive tracers, completely at the mercy of the surrounding flow; large, massive things can pass through even strong turbulence without being affected too much by it. In between, there is a continuum of spatiotemporal complexity where suspended matter is intermittently affected by turbulence. We will explore these intermediate scales and their physics, and discuss what they can teach us about both engineering and biology.

Nature creates beautifully crafted functional inorganic structures to supplement biological functions, from structural support to enhanced optics. These tissues known as biominerals have garnered the attention of biologists and materials scientists alike, the latter aiming to emulate similar properties into their own synthetic materials. To that end, we have developed a novel artificial mineralization vesicle capable of directed synthesis of organic-inorganic composite materials.

Sum Frequency Generation (SFG) vibrational spectroscopy has demonstrated an ability to distinguish crystalline cellulose from its surrounding amorphous polymers. Conventional SFG systems reveal information about the packing, distance, and orientation of cellulose crystals in macroscopic scales. However, macroscopic characterization techniques provide volume averaged information which can mask key structural details. To tackle this problem, our group developed a state of the art SFG-microscopy system, which gives us the ability to study smaller regions (<10 microns). I will discuss why these small regions are important and how SFG-microscopy can be used to enhance the study of plant mutation and plant development.

Electric fields are a convenient tool for the fabrication of ordered nanostructures because they can be applied instantly, localized precisely, and scale favorably with dimensions relevant to nanofabrication techniques. Although polymeric materials are increasingly used in electronic applications, their physical behavior in the presence of electric fields is not well understood. Defined polymer structures have significant relevance in a variety of thin film applications. Here, light‐mediated polymerization and highly efficient ‘click’ chemistries in a stop‐flow lithographic setup provide a powerful platform for fabrication of hierarchical surface‐grafted polymer brush architectures from uniformly functionalized substrates.

With cryo electron microscopy (CryoEM) in the spot light these days, it's important to be aware of it's different flavors, as well as the complimentary technologies that have developed in tandem. In this talk I will focus on the use of electron cryotomography to study molecules in their cellular context, the development of cryo-focused ion beam milling for imaging within mammalian cells and tissue, as well as cryo-fluorescence microscopy for targeting specific molecules within the cell. I will also touch on the current challenges to be overcome as cryogenic imaging moves into the future.