Each year, researchers from across Penn State enter amazing images representing their research in materials into the Material Visualization Competition (MVC).The seventeen images below are all entries from 2020 (the twelfth year for the MVC) .
The MVC truly celebrates the quality of research in materials being conducted at Penn State.
Artist’s Statement: 2D materials are a field of study where a 1nm change in scale can have dramatic effects. This work captures that fact, and its connection to the “MATSE tetrahedron”, the interrelated nature of properties; structure; processing; and performance, which lie at the heart of the discipline. The colors observed are from different thicknesses of Bi2Te3, indicating the layer-dependent properties of layered materials. 1-5 layers are shades of green and blue while 6-10 transition from purple to pink and white. Thick white layers grow in lines at 60o from one another, capturing the symmetry of the underlying WS2. These formations lie atop grain boundaries in WS2, where thicker crystals nucleate. This highlights the interconnected nature of the MATSE tetrahedron: layer dependent properties are determined by the defect structure of the underlying WS2. Structure is in turn related to processing parameters during growth. All of these interrelated factors will affect the performance of the material.
Scientific Process: The sample was prepared by a two-step process. First, chemical vapor deposition was used to grow a three-atom thick monolayer of WS2 on a SiO2/Si wafer. Second, Bi2Te3 was thermally evaporated to grow heterostructures. An optical micrograph was captured with a CCD camera and is presented here without any image manipulation.
Artist’s Statement: In this piece, I was deeply drawn to the scale-like cellular structures that were of interest in this material. The steely scales were then also emphasized through the natural sectioning that occurred between melt pool passes. These sections and scales reminded me of reptiles, and particularly snakes. I am personally terrified of snakes, although I know they are an essential part of the healthy ecosystem that Happy Valley is part of. With the inspiration of expressing the slithery aptitude of the image and maybe spreading a more positive mentality around snakes than I usually share, I used coloration similar to a milk snake with the natural melt pool sections as the sections of the snake. These colors particularly standout to me and I hope that they make the piece pop to the audience while reminding them of a scaly creature as well.
Scientific Process: 17-4 PH stainless steel is a popular alloy for production via powder bed fusion additive manufacturing. When produced in this process, the as-deposited microstructure often varies significantly from wrought. Here, a sub-grain cellular dendritic structure on the order of a couple microns is noted after electrolytic etching of an as-deposited structure. Although these sub-grain, cellular structures appear inside individual melt layers, grain structures are often carried over between melt pool passes. The cellular structure can provide increased strength in comparison to the large grains as measured using other techniques but is usually indicative of retained austenite that is unheard of in the wrought counterpart of this alloy.
Artist’s Statement: Objects with core-shell structures can be found in many places in the world, from the artificial composites with nanoscale to the Earth. This picture exhibits this amazing structure from a micro perspective. It appears that two materials with different physical properties are closely linked.
Scientific Process: 17-4 PH stainless steel is a popular alloy for production via powder bed fusion additive manufacturing. When produced in this process, the as-deposited microstructure often varies significantly from wrought. Here, a sub-grain cellular dendritic structure on the order of a couple microns is noted after electrolytic etching of an as-deposited structure. Although these sub-grain, cellular structures appear inside individual melt layers, grain structures are often carried over between melt pool passes. The cellular structure can provide increased strength in comparison to the large grains as measured using other techniques but is usually indicative of retained austenite that is unheard of in the wrought counterpart of this alloy.
Artist’s Statement: We usually describe surfaces by their color and surface texture as those appear to the eye. Highly appealing surfaces to humankind are the shiny, refracting, and highly reflecting surfaces of polished crystals with exotic colors, better known as gemstones. As flat, static and robust polished facets of gemstones are perceived, they reveal a whole different appearance at the atomic scale. Here, we are looking at an ultra-flat, polished surface of corundum, i.e. Sapphire. The surface texture at the atomic level is far from flat. On the contrary, the presented terraces with wavy edges seem to steadily flow over the surface following their very own dynamic.
Scientific Process: Polished high-precision cuts through crystals are never perfectly flat due to minimal misalignments during the cutting process. Instead, the surface is composed of atomic step terraces with straight or irregular shaped edges as this atomic force microscopy image of an ultra-clean corundum crystal reveals.
Artist’s Statement: Defects in materials are fascinating for their structural features and they tremendously affect the material properties. Even though there are many ways to study defects in materials, directly visualizing them in their native form is very powerful to understand their complex structures. To that end, this image is taken from an electron microscope which is powerful enough to resolve features at nanometer length scales. This enables us to look at the defects present in materials and understand their origin (dislocations in 2D material in this particular example).
Scientific Process: The picture is a dark field transmission electron microscope (DF-TEM) image taken from a two-dimensional (2D) material. It shows a network of dislocations present in the sample highlighting the presence of strain in the sample presumably to accommodate the epitaxy with substrate. Furthermore, the dislocations appear to form triangle shapes in some areas which could be related to the hexagonal symmetry that is a characteristic of 2D materials. The spacings between the dislocations seen are in the range of 5-10 nm thus underlining the power of TEM in resolving features at nanometer length scales. The image was taken using FEI Talos TEM at MCL.
Artist’s Statement: An artist’s ability to visually solve problems can bring a new sense of creativity to the questions and problems we face in science. On the other hand, the research and critical thinking skills used in science teaches me to keep detailed notes, experiment with different artistic techniques, and push me to explore new ways of thinking. This interplay creates space for scientists and artists to learn from one another. In combining my materials science and artistic research, the audience experiences my processes firsthand. Artistically, I am converting the traditionally functional forms of bowls and providing them a more delicate and aesthetic purpose. Both ceramics thrown on the wheel and glass formed in a lab take careful skill developed through experience, experiment, and an understanding of theory. By fusing glass and ceramics in these pieces, you learn to visualize and understand the similarities of art and scientific research.
Scientific Process: Glass forming: Glass compositions used range from vanadium tellurites to alkali borates. For each composition, chemicals are mixed with the correct stoichiometry (in the case of the .4TeO2-.6V2O3 or .7TeO2-.3V2O3 glasses) and melted in platinum crucibles ranging from 700 – 1200 °C. Molten glass is poured and then quenched between two metal plates. For these art pieces, chunks of glass were placed at the bottom of the glazed ceramic bowls and re-fired in a kiln. Pools of glass and re-crystallized areas can be seen inside the different bowls. Ceramic bowls: Each bowl is made of white stoneware and is formed on a pottery wheel. The bottoms of each bowl were trimmed to remove excess clay, and once they were completely dry were fired in a kiln to create bisqueware. Three different surface finishes were applied: a white shiny glaze, a yellow/green glaze, and black slip with a clear shiny glaze layered on top.
Artist’s Statement: The image as seen has come directly from my microscope image and has not been retouched at all. When focusing the microscope on the hydrogel fiber, I was surprised to see the incongruence in the fiber’s diameter. I had not been able to focus on a resubmerged fiber so well before, and it has taken many trial and errors to figure out the best way to get good images for our research. Getting this very sharp image is great so that we can see and compare this recovered hydrogel to others to advance our research and what we know. We know that there is uniformity in hydrogels that have not been previously strained, so the bumps on the edges are most likely from plastic deformation from straining the hydrogel. Further research is being done to study this observable phenomena.
Scientific Process: I am studying the mechanical properties of hydrogel fibers created through a rapid injection process. They are made from ABA triblock copolymers, with hydrophobic (A blocks) ends and a hydrophilic (B block) center. This feature causes the hydrogel to form when injected into a B selective solvent such as water. After they are created, we strain the fibers to various lengths and let them dry. Then, to study their recovery properties, they are placed back in water. The diameter and length are measured before and after submerging. The optical microscope is used to measure the diameter, as well as get a closer look at what is happening to the fibers during the process. The fiber seen in the image had been strained to 5x its original length, and then placed back into water. When placed back into water, the fiber never goes back to its original length and diameter due to plastic deformation, as seen by the incongruency in the fiber.
Artist’s Statement: Scanning electron microscopy image of a breast tumor in its microenvironment. Metastatic cancer cells, labeled in green, are migrating away from the primary tumor and invading into the surrounding matrix to form tumors at secondary locations.
Scientific Process: Breast tumor cells invading into the surrounding fibrous protein matrix.
Artist’s Statement: The unmelted powder and the fracture surfaces have an analogy of an island used to be buried under the ocean before tidal weaves open up it.
Scientific Process: Fracture surface of tensile tested Ti-6Al-4V sample shows partially melted powders on a high magnification Scanning electron microscope (SEM) image. The image focuses on unfused parts on additively manufactured (AM) sample, which is produced with 1500W laser power. The partially melted powders sit on a floor of previously formed grains have very fine alpha laths. The deformation is seen clearly on the fractured parts, which are colored for an artistic purpose.
Artist’s Statement: Growing up in Long Island—fifteen minutes from the ocean—I found myself daydreaming about the beach every moment of the school day. If I was not at school, I was by the ocean, walking the boardwalk, listening to the waves crash, or taking in the breeze coming off the watery front. It seems that I may never shake this feeling because after imaging my rhenium samples I found myself thinking of the beach once more. Using a Nikon L200ND optical microscope at 10X, Rhenium films deposited on a sapphire substrate were imaged. The sapphire substrate represents the ocean, while the rhenium films represent the sand.
Scientific Process: Thin-film deposition of rhenium can be achieved by using electron-beam evaporation. However, given the rapid rate of deposition and film thickness of 100 nanometers, the film underwent stress that gave way to this unique image that resembles a sandbank. Thin layers of rhenium peeled back onto itself while some remained adhered to the sapphire substrate. Image was captured using an optical microscope.
Artist’s Statement: In a normal winter day that mixing calcium and carbonate ions in the lab results in the formation of most stable, boring micro-box structures of calcite, we could engineer the ion interactions with our magic additive to form calcium carbonate micro-plants in the lab! Here is how we bring spring into our lab during the winter!
Scientific Process: A scanning electron microscopy (SEM) image of a rare amorphous calcium carbonate (ACC) micro-branch decorated with vaterite micro-buds. Here, the most thermodynamically unstable polymorphs of calcium carbonate, ACC and vaterite, are stabilized at an ambient condition via macromolecular biomimetic mineralization. Inspired by the mineralization pathways in living organisms, we have developed a family of dendrimers based on the symmetric decoration of tetra ethylene glycol with phosphonate groups to engineer the interactions of precipitating ions and stabilize early-stage polymorphs at room temperature and atmospheric pressure. These structures may resemble some of the hard organs in vertebrates, which may enable synthetic, acellular tissue engineering. More information may be found in DOI: 10.1039/C8QM00301G.
Artist’s Statement: Saying goodbye to the deep blue ocean and the golden sunflowers, summer by the sea finally gives way to autumn by the mountain, embracing the amber leaves and purple sunset. They will finally be buried by the icy and snowy winter. Day after day, season following season, I maintain a well-ordered life in a world full of disorders while craving for subtle changes within the repetitions.
Scientific Process: The hierarchical ferroelectric domain structure consisting of twinning nanodomains form spontaneously on the surface of a (111)-oriented lead titanate thin film under a partially screened condition, which is predicted by phase-field simulations. The domain pattern exhibits a quasi-6-fold symmetry, illustrating the six degenerate states variants with polarization pointing toward one of the six directions of a tetragonal unit cell, e.g., [±100], [0±10], and [00±1].
Artist’s Statement: My inspiration for this submission came from the way light interacts with oil on water, like spilled gasoline on wet pavement. Just like oil, polystyrene doesn't mix with water. I like to envision the hydrogel network as forming from a mesh of millions of tiny iridescent bubbles strung together to form a multicolored web.
Scientific Process: The network shown is formed as a result of the phase separation of polymer chains composed of two end segments of polystyrene and one middle segment of polyethylene oxide. Polystyrene will not dissolve in water, so when the polymer is exposed to water the polystyrene ends of the molecules will cluster closely together. The only thing keeping the polystyrene from precipitating out of the water is the polyethylene oxide segments bridging the polystyrene clusters. The polystyrene clusters group together to form a mesh, resulting in the beautiful network microstructure of the hydrogel shown in the image.
Artist’s Statement: The microstructure inspires imagery of lightening bolts across a starry night sky.
Scientific Process: The image shows the microstructure of a precipitation hardenable aluminum alloy joined using friction-stir welding. The grain boundaries are outlined in yellow and precipitates can be observed within the interior of the grains. Friction-stir welding is a solid-state joining process which joins a metallic workpiece without melting. This joining process offers advantages over traditional fusion welding processes because issues which develop when cooling from a liquid to a solid phase are eliminated (such as liquation and solidification cracking). The sample was prepared using standard metallographic techniques and etched using Werk’s reagent. The image was taken using dark field optical microscopy at 500x magnification.
Artist’s Statement: The microstructure inspires imagery of looking through a single snowflake falling through the sky, where the sun light is refracted by the ice crystal and the seven colors of the visual light spectrum manifest within the voids.
Scientific Process: The image shows the microstructure of a 2209 duplex stainless steel alloy fabricated using a laser-based directed energy deposition additive manufacturing process. Duplex stainless steel alloys obtain their high strength and corrosion resistance from a dual ferrite/austenite microstructure. In this image the austenite phase is white, while the ferrite phase appears as the seven colors of the visual light spectrum. The sample was prepared using standard metallographic techniques and etched using a KOH electrolytic etch. The image was taken using optical microscopy at 500x magnification.
Artist’s Statement: The layer-like structure of polybutadiene-block-poly(ethylene oxide) (PBD-PEO) film makes people connect with ocean, where the lamellar are spreading away and forming waves.
Scientific Process: Beautiful wave-like pattern is captured by scanning electron microscopy, where polybutadiene-block-poly(ethylene oxide) (PBD-PEO) copolymer self-assembled into lamellar morphology simply by solvent cast method. Self-assembly of block copolymer has become an efficient and powerful way to obtain ordered structure from nanometer scale. PBD-PEO with lamellar structure is a potential one-dimensional photonic material, where the ordered domains are capable of being expanded by solvents as large as four times and the resulting swollen domains are able to reflect green light.
Artist’s Statement: When we discuss additive manufacturing of metallic components, the melting process is one of the key components. However, as with all processes, this melting process is never perfect. Fabricated samples can end up with unmelted powder particles. When viewed in two dimensions, such as on a flat, polished surface, the imperfections are highlighted; but when viewed in three dimensions, these powder particles almost look purposeful.
Scientific Process: The image unmelted powder particle on the unpolished surface of a cracked additively manufactured sample was captured using scanning electron microscopy. In this image you can see the rough surface of a small piece that broke off from the larger sample. Embedded in this cracked piece was a small unmelted powder particle. The depth of field that highlights the dimensionality of the powder particle can best be captured using SEM imaging.
