Complete MVC 13 Gallery
“Showcasing a novel gas sensing platform based on a highly porous, stretchable laser-induced graphene pattern by a group of researchers led by Ning Yi and Prof. Larry Cheng at Penn State”
Ning Yi, Graduate Student, Materials Science and Engineering
Artist’s Perspective: The novel gas sensing platform based on a stretchable laser-induced graphene pattern on the skin surface of the panda allows continuous and direct measurements of the biomarkers from the body and exposed environments while learning kung fu. The large specific surface area of the laser-induced graphene foam and various gas-sensitive nanomaterials is showcased by the highly porous foam in the elevated stage where the panda practices kung fu. Multifunctional on-body sensors can precisely and continuously monitor the health conditions of the body, whereas the wireless transmission modules can wirelessly power up the sensors and transmit the data generated from them to the cloud for real-time analysis.
Scientific Process: Here, a novel gas sensing platform based on a highly porous laser-induced graphene (LIG) pattern is reported. The LIG gas sensing platform consists of a sensing region and a serpentine interconnect region. A thin film of metal coated in the serpentine interconnect region significantly reduces its resistance, thereby providing a localized Joule healing in the sensing region during measurements of chemo resistive gas sensors. Dispersing nanomaterials with different selectivity in the sensing region results in an array to potentially deconvolute various gaseous components in the mixture. Taken together with the stretchable design layout in the serpentine interconnect region to provide mechanical robustness over a tensile strain of 20%, the gas sensor with a significant response, fast response/recovery processes, excellent selectivity, and an ultralow limit of detection (1.5 parts per billion) at a modest temperature from self-heating opens new opportunities in epidermal electronic devices.
“Island in a Steel Sea”
Derek Shaffer, Graduate Student, Materials Science and Engineering
Artist’s Perspective: In this piece, I was deeply drawn to the isolation of the brittle area around what looks like waves of ductile dimpling. The steely waves then made me think of water and the isolation of a deserted island. The coloring I utilized then made this abundantly clearer as if looking at a simple map of an island in a sea of steel. While Happy Valley may not have a sea or an ocean coast, there are many lakes in the area and some even have islands of their own! These unexplored territories and habitats that this image reminded me of further connected me, my home, and this piece in my mind and my heart. These colors particularly standout to me as well as the general shape and topography of the image and I hope that they make the piece pop to the audience while reminding them of unfound, isolated lands 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 brittle fracture area is noted in the as-deposited structure. These brittle areas can often be connected to the micron scale inclusions present from powder production and throughout additive manufacturing. This brittle behavior is most common in argon atomized material, but nitrogen atomized material usually has some amount of retained austenite that is unheard of in the wrought counterpart of this alloy and leads to increased ductility.
“Made from Scratch: Scratch Induced Birefringence in Conjugated Polymer Indacenodithiophene-co-benzothiadiazole (IDT-BT)“
Abigail Fenton, Graduate Student, Chemical Engineering
Artist’s Perspective: This unedited image calls to mind the beautiful blue Morpho menelaus butterfly, which has strikingly blue wings that are delicate but powerful. Like the Morpho menelaus butterfly, this conjugated polymer thin film gets its color from its unique nanoscale structural properties and not because it is pigmented.
Scientific Process: This image of a thin film high performance conjugated polymer, IDT-BT, was taken under crossed polarizers at 20x magnification in an Olympus BX53M microscope. Unlike most polymers that are insulating, conjugated polymers can conduct electrons along their backbones due to delocalized pi orbitals and therefore are used in various organic electronic devices such as organic light emitting diodes (OLEDs), organic field effect transistors (OFETs), and organic photovoltaics (OPVs). Due to their intended applications these polymers are designed to utilize the full visible light spectrum and have unique optical properties due to their phase behavior. The bright colors in this image arise from local polymer chain alignment caused by rubbing tweezers against the thin film surface. Aligning these polymer chains over large areas through rubbing can increase the pathways for charge transport across the film, leading to better device performance, but can also reveal beautiful birefringent colors.
“Graphene x Andy Warhol“
Zach Trdinich, Undergraduate Student, Materials Science and Engineering
Artist’s Perspective: I remember seeing the MVC winners from past years hanging in Steidle during my campus tour and thinking, “Wow, I hope one day I will be able to do something like that.” Now here I am, 2 years later, submitting my own image for MVC 13. Andy Warhol is well known for his pop art, and since I grew up in Pittsburgh like him, I couldn’t resist drawing the comparison to my image. My piece is authentic, straight out of the Nano Scope software. I know it will be hard to compete with the extraordinary computational and SEM images, but I firmly believe I have made the best possible submission I could with the tools and knowledge I have.
Scientific Process: This image was produced via AFM (Atomic Force Microscopy). The colors present a “topographic map” of sorts for the sample, with yellow being the lowest points and blue representing the highest. This is all on a scale of -1.5 micrometers to 1.5 micrometers. The sample is 2D-GaN encapsulated between graphene and SiC which has great potential in the semiconductor industry if its synthesis can be repeated.
“Formation of a discotic liquid crystal: Nucleation, growth, and coalescence of mesophase spheres driven by the principles of chemistry and physics into a visual narrative of science with line, shape, color, texture, and space as shown in a polarized-light micrograph“
Sara Andreoli, Postdoctoral Scholar, EMS/Energy Institute
Artist’s Perspective: This is a microscope image of a semi-coke obtained from carbonization of a petroleum feedstock in a laboratory reactor. To the naked eye, it appears black, similar to coal. “The color black relates to the hidden, the secretive and the unknown, and as a result it creates an air of mystery.” A polarized-light microscope may uncover this mystery and liberate the colors blue, yellow, and magenta by the interaction of polarized-light with anisotropic carbons. Capturing all three stages of mesophase development in just one image offers a powerful visual narrative of the dynamic process with changes in shape, color, and texture of objects from the birth of mesophase spheres (nucleation) on the right of the image to their growth and interaction with others (coalescence), and into their full maturation into anisotropic domains on the far left. In addition, the memory of these interactions is retained with patches of yellows and blues remaining from individual spheres that were coalesced.
Scientific Process: A polarized-light micrograph of a petroleum semi-coke sample illustrates the nucleation of mesophase spheres (on the right), their growth and coalescence (moving toward the left) to form anisotropic domains (on the left). Blue and yellow colors in the micrograph result from the interference of reflected polarized-light and indicate an anisotropic texture of the mesophase produced by laboratory carbonization from the isotropic pitch matrix, areas with magenta color. Carbonization chemistry controls the generation of mesogens and physics dictates minimization of interfacial surface energy during spheres nucleation and growth and coalescence into anisotropic domains. The size, shape and spatial arrangement of isochromatic areas, the optical texture, helps assess the precursor’s potential for manufacturing a solid carbon crystal, graphite. Synthetic graphite is used in electrical-arc furnaces for recycling scrap iron and steel.
“Rigidity of the extracellular matrix surrounding the cell promotes Epithelial-Mesenchymal Transition”
Chimnay Sankhe, Graduate Student, Chemical Engineering
Artist’s Perspective: My research is based on the big-picture of understanding how the mechanical properties of a tissue regulate cell signaling pathways. If we can better understand how cells behave in response to tissue mechanics, we can develop strategies to target the signaling pathways and in turn, negate pathological conditions such as cancer and fibrosis. My current work involves studying the effect of modulus of the cell’s extracellular matrix on chromatin architecture and how it affects gene transcription machinery during the process of Epithelial-Mesenchymal Transition (EMT). The picture I am trying to convey with the help of my image submission is that mechanical stimuli can independently regulate the expression of proteins in epithelial cells during the process of EMT. Hence, I combined fluorescence images taken for EMT-induced epithelial cells that were seeded on increasing matrix rigidities to show the audience how the increase in modulus enhances EMT-induced protein expression in cells
Scientific Process: The relationship between the extracellular matrix (ECM) mechanics surrounding a cell and cell function is dynamic as cells can remodel and respond to changes in their local microenvironment. Epithelial-Mesenchymal Transition (EMT), an important physiological process important during wound healing and organ development, contributes to pathologies such as fibrosis and cancer. The images captured with an epifluorescence microscope shows EMT-induced mouse mammary epithelial cells cultured on 300 Pa and 6300 Pa (left and middle) polyacrylamide hydrogels and the glass substrata (right). Nuclei are colored blue and the mesenchymal protein marker α-smooth muscle actin (SMA), component of cell’s microfilaments, is indicated in red. On soft 300 Pa substrate, EMT-induced cells are not able to express α-SMA but as the rigidity of the substrate is increased to 6300 Pa and to glass (~GPa), EMT-induced cells are able to express enhanced expression of α-SMA. Thus, matrix rigidity regulates EMT.
“If Plants Grew like Lithium Niobate Crystals, then I’d Plant a Garden of Sunflowers”
Katy Gerace, Graduate Student, Materials Science and Engineering
Artist’s Perspective: While black and white electron images are quite possibly the farthest thing from a colorful garden, the radially growing lithium niobate crystals wedged between potassium niobium silicate oxide reminded me of blossoming flowers. As a dabbling gardener myself, I usually focus my energy on growing vegetables. But no matter how hard I try, stray sunflowers always seems to pop-up in the veggie garden. Always appearing with nothing more than soil and sun, sunflowers represent the all-to-easily formed lithium niobate crystals in my SiO2-Nb2O5-Li2O-K2O glass system. Just like sunflowers grow in the garden, lithium niobate crystals grow in my glass-ceramic, producing a beautiful bouquet of flowering crystals in a garden of glass.
Scientific Process: Glass-ceramics are produced through controlled nucleation and crystal growth of a crystalline phase within a non-crystalline glass matrix. This image captures a silica-based glass matrix with lithium niobate (orange and yellow sunflowers) and potassium niobium silicate oxide (green leaves) crystalline phases. It was taken using back-scattered electrons on a scanning electron microscope (SEM). Through oriented crystal growth of ferroelectric crystals such as lithium niobate, anisotropic properties such as piezoelectricity are introduced to glass which is inherently isotropic. Oriented crystal growth in glass-ceramics offers a novel way to produce piezoelectric materials while maintaining the unique formability of glass.
“Aerial View of Potassium Niobium Silicate Oxide Ice Mountains”
Katy Gerace, Brittany Hauke and Matthew Mancini
Artist’s Perspective: While the cold winter months may weigh heavy on some, I look forward to the brisk winds and billowing snow drifts that accompany winter. With my boots, hat, and coat, I welcome the invigorating cold air as I trudge up mountains and scurry across wind-swept fields. Looking at this image, I was reminded of mountain tops covered in snow and ice. While my personal views of mountains are typically limited to magnificent vistas seen from neighboring peaks, this image gave me a unique perspective as I imagined myself looking down the electron gun to enjoy an aerial view of mountains covered in ice crystals waiting to be conquered. From this perspective, snowy cliffs and exotic microstructure are not daunting, but inspiring as they present unique opportunities to explore uncharted territory.
Scientific Process: Most glass-ceramics require an acidic etch to visualize their microstructure using scanning electron microscopy (SEM). In this image, however, only a colloidal silica final polish was required to illustrate the extensive three-dimensional microstructure of a silica-based glass-ceramic with different niobate crystalline phases. This image was taken with a SEM using a secondary electron detector and shows potassium niobium silicate oxide crystals (white) on a dark background of lithium niobate crystals and silica glass.
“Heavenly Patterns: Widmanstätten Microstructure in Additively Manufactured Duplex Stainless Steel”
Youssef Refaat Ali, Graduate Student, Additive Manufacturing and Design
Artist’s Perspective: I still remember the day I first used a microscope to look at onion cells back in middle school. I was astonished at what lies beyond the view of the naked eye. Fortunately, till this day I am still in awe of the world found under a microscope. Microscopy helps us understand much more about material systems and how new sustainable means of manufacturing influence them. Additive manufacturing is a gateway to new discoveries that will eventually improve upon traditional manufacturing methods resulting in more cost-effective and advanced materials with better properties. As the perseverance rover recently landed on the surface of Mars, one day the next mission will be carrying a 3D printer capable of printing materials on the spot aiding the journey of interplanetary travel.
Scientific Process: Widmanstätten microstructure, naturally occurring in iron-nickel meteorites that fell thousands of years ago, has been observed in 2205 duplex stainless steel fabricated using additive manufacturing. In this image, austenite is the observable dark grain while the lighter background is ferrite. SEM imaging revealed that “needle-like” Widmanstätten austenite grains grow from grain boundaries under high cooling rates and temperatures exceeding 1000K observed during additive manufacturing. Compared to other austenite morphologies in this image, this type of grain increases material hardness and mechanical properties. This image was obtained using the Apreo scanning electron microscope at a magnification of 5,000x.
“Interconnected microporous structure of tung oil and poly(ε-caprolactone) semi-interpenetrating polymer networks”
Samy Madbouly, Faculty, School of Engineering, Plastics Engineering Technology, Behrend, Erie
Artist’s Perspective: This picture observed by scanning electron microscopy. I was very surprised to see a wonderful black and white microscale morphology of semi-interpenetrating polymer networks that you may be able to see similar large-scale pictures when you are diving in the deep ocean.
Scientific Process: Semi-interpenetrating polymer networks of bio-based poly(ε-caprolactone) (PCL) and polymerized tung oil have been prepared via in situ cationic polymerization and compatibilization in a homogeneous solution. This novel blending technique produced a microporous morphology with open three-dimensional interconnected cluster structures. The porous morphology was found to be composition-dependent (the pore size and interconnectivity decreased with increasing PCL content in the blend).
“A dual-phase microstructure of a 3D-printed stainless steel alloy”
Andrew Iams, Graduate Student, Materials Science and Engineering
Artist’s Perspective: The image shows the dual-phase microstructure of a duplex stainless steel alloy fabricated using additive manufacturing, also known as 3D printing. This dual austenite and ferrite microstructure, which etched blue and yellow respectively in the image, contributes to the high strength of these alloys. Additive manufacturing provides a processing route to produce a fine austenite grain morphology, compared to traditional wrought duplex stainless steel alloys. This fine microstructure can more effectively inhibit dislocation motion during plastic deformation, resulting in improved strength over traditional wrought products.
Scientific Process: The material was fabricated using a nitrogen atomized duplex stainless steel (UNS S32205) powder feedstock and a laser-based directed energy deposition additive manufacturing process. Specimens for metallographic analysis were extracted from the material, mounted, ground (SiC grinding paper to P4000 ISO grit size), and polished (to 1 µm diamond slurry) using standard techniques. Samples used for optical microscopy were etched using a KOH electrolytic solution (25 g KOH, 50 mL distilled water, 5 VDC for 5 sec). In order to reveal the austenite/ferrite microstructure and to distinguish between the different austenite morphologies, a Nikon Epiphot inverted microscope was used under x50 magnification.
“Never-ending Friendship: Titanium(IV) isopropoxide (TTIP) decomposition on SrO terminated SrTiO3”
Benazir Fazlioglu Yalcin and Dundar Yilmaz
Artist’s Perspective: As a child of immigrants who moved from the former Yugoslavia to Turkey and now an international student in the US, the concept of friendship has been very meaningful for me my entire life. Wherever I have been, the friends who received me with open arms broadened my horizons and motivated me to discover more outside my little family. Likewise, there is a never-ending friendship between TTIP and SrO-terminated surface where TTIP discovers itself as well as its environment. That way, this tiny TTIP molecule is finally able to be a harmonious part of the atomic community in which it is more than welcome
Scientific Process: The surface kinetics of molecular beam epitaxy (MBE) has been puzzling scientists for many years. Non-volatile metals such as Sr have been used alongside volatile metal-organic substances to grow epitaxial thin films without requiring high temperatures. This has paved the way for many unanswered questions—one of which is searching for surface compositions that will result in higher growth rates. TTIP is shown in this image as a metal-organic substance and a key component of SrTiO3 growth. To lift the veil of the mystery, TTIP molecules and SrTiO3 with both TiO2- and SrO-terminated surfaces have been visualized in a molecular dynamics simulation (ReaxFF). TTIP prefers decomposing in the vicinity of the SrO-terminated surface which catalyzes the decomposition while no TTIP can be observed on the TiO2-terminated surface. This result explains why SrO-termination provides a 40% higher growth rate than TiO2-termination in the literature and plays an important role as a critical puzzle piece.
“Microscopic Magnesium Meteor”
Patrick Rondomanski, Graduate Student, Materials Science and Engineering
Artist’s Perspective: Beautifully falling into the unknown. This crystal appears to fly across a world that is strange from itself. Like a magnesium-rich meteor falling to Earth, it lights up and lets the world know of its arrival. I was inspired to represent this crystal as a meteor because the odds of this crystal forming are comparable to a meteoroid entering Earth’s atmosphere. Space is infinitely large and the likelihood of any specific meteoroid reaching Earth is improbable, just like the probably of this lone magnesium crystal forming in its boron-rich environment.
Scientific Process: Presented here is a scanning electron microscopy (SEM) image of a single crystal of magnesium grown via hybrid physical-chemical vapor deposition (HPCVD) on a c-plane sapphire substrate. This crystal is the result of a supersaturation of magnesium vapor and an absence of diborane along a region of the substrate during a MgB2 growth. Although this hexagonal crystal was unintentionally made, it represents the influence of fast versus slow growth rate on crystal growth with its short wide “head” and long tapering “tail”.
“Gold droplets on graphene leaf”
Rinu Abraham Maniyara, Postdoctoral Scholar, Materials Science and Engineering
Artist’s Perspective: My passion for photography always makes me to make an analogy between my work to the daily life. This work explores the relationship between scientific output of my experimental work of gold metal intercalation on graphene surface to the the real-life water droplets on leaves. As the real scientific output image is a colorless, I wanted them to turn around into a colored daily life image that my audience is familiar with. For that I have retouched them using photoshop software and made a colorful one.
Scientific Process: Scanning electron microscope image of two-dimensional gold intercalated on epitaxial graphene/silicon carbide substrate through Confinement Heteroepitaxy. The gold nanoparticles above the graphene surface are residual particles after the intercalation process.
“Templating Mechanism in Carbon Nanotubes Composite Films”
Malgorzata Kowalik, Faculty, Mechanical Engineering
Artist’s Perspective: The background is a tunneling electron microscope (TEM) image of the graphitized composite film. The graphitized layers of polymer matrix can be observed in the proximity of carbon nanotubes (CNTs). The reactive simulations provide an atomistic view of the chemical changes responsible for a templating mechanism leading to this graphitization. The simulations snapshots of the composite system (CNTs with polyacrylonitrile) after 1ns carbonization simulations at 1500K generated with VMD visualization software are represented in colors. All polymer atoms are translucent and newly evolved all-carbon rings (a starting point for the graphitic structure) are gray clustered polygons. The CNTs are represented only with the carbon-carbon bonds.
Scientific Process: Carbon nanotubes addition provides not only reinforcement, but also nanoscale confinements for a matrix material. The presence of highly align CNTs alters the carbonization properties of these composite materials. We used the ReaxFF method to identify the underlying molecular changes responsible for this low-temperature graphitization. The enhanced all-carbon ring production observed in the presence of the carbon nanotube can be used to explain experimentally observed epitaxial growth of anisotropic graphitic crystals leading to the graphitization of these composite materials at a much lower temperature, then the graphitization temperatures characteristic for the traditional carbon fibers.
“The Shell – Additive manufactured Ti-6Al-4V fracture surface”
Qixiang Luo, Graduate Student, Materials Science and Engineering
Artist’s Perspective: The spherical gaseous pores have fine shell structure with elegant whirls that initiated from the melt pool solidification on boundary of gas and solid alloys. There are both single placed shells and overlapped ones that separated all over the fracture surfaces, and their unique neat fashion make them stand out compared to the messy crack networks and failure cliffs.
Scientific Process: The laser powder bed fusion manufactured Ti-6Al-4V material has relative stronger tensile properties but weaker ductility, and one of the reason for that is the massive number of pores during melting and solidification process of the alloy. These large gaseous pores are often the sources for internal crack that eventually leads to failure of the material. And the image here shows the fracture surfaces under SEM, where the shell features are the spherical gaseous pores, also associated with deeper irregular pores that can be the region that initiate the cracks.
“Mixed Chromium Oxide in the Shape of a Skull”
Shannon McGee, Graduate Student, Chemistry
Artist’s Perspective: As many discoveries are sometimes made, I came upon this surface defect entirely by chance during the characterization of this sample with Raman spectroscopy. Imagine my surprise while collecting a spectrum to see a skull looking back at me! The morphology of our samples created through laser-induced thermal synthesis have been well studied through other methods such as scanning electron microscopy and profilometry. This image reminds us to always keep our eyes peeled for discovery in our research, whether it’s noticing a unique surface feature while collecting a spectrum or finding new properties in a material.
Scientific Process: Through laser-induced thermal voxel (LITV) synthesis, many individual and/or multimetal materials are able to be directly synthesized and patterned on substrates through facile deposition from liquid precursors. This non-equilibrium synthesis method creates a high temperature, microscale solvothermal reactor in solution where precursor compounds in the solution are thermally decomposed to produce nanoparticle composites which become sintered to the substrate while the laser is scanned. This deposition of a mixed chromium oxide was synthesized from a chromium nitrate precursor salt dissolved in ethylene glycol. Through facilely changing or mixing precursor salts in solution, we can affect various properties such as oxidation state, morphology, and electronic behavior to study how such variables affect material’s performance in catalysis, sensors, and other fields of interest.
“Chirality-induced conformational disorder in relaxor ferroelectric polymers”
Yang Liu, Postdoctoral Scholar
Scientific Process: The direct structural imaging of conformational disorder in relaxor ferroelectric polymers is provided using atomic force microscope infrared spectroscopy. This mapping of disordered chain structure at the molecular level offers unprecedented fundamental insights into origin of relaxor behavior in polymer ferroelectric materials. The direct structural imaging of conformational disorder in relaxor ferroelectric polymers is provided using atomic force microscope infrared spectroscopy. This mapping of disordered chain structure at the molecular level offers unprecedented fundamental insights into origin of relaxor behavior in polymer ferroelectric materials which are the materials of choice for electrostrictive actuators, energy storage capacitors, electrocaloric cooling and piezoelectric sensors.
“Multimetal Particles Sintered to Glass Substrate”
Shannon McGee, Graduate Student, Chemistry
Artist’s Perspective: When I first saw this film, I was vaguely reminded of an abstract night sky with the gray substrate resembling the vast space that was then dotted with stars (Fe/Co/Ni oxide particles in reality). As I continue my research in the Zarzar group at Penn State, I am thankful of these moments where I can repeatedly experience the awe and wonder of scientific observation
Scientific Process: Through laser-induced thermal voxel (LITV) synthesis, many individual and/or multimetal materials are able to be directly synthesized and patterned on substrates through facile deposition from liquid precursors. This non-equilibrium synthesis method creates a high temperature, microscale solvothermal reactor in solution where precursor compounds in the solution are thermally decomposed to produce nanoparticle composites which become sintered to the substrate while the laser is scanned. The imaged sintered particles of a multimetal mixed oxide were synthesized from iron nitrate, cobalt nitrate, and nickel nitrate precursor salts dissolved in ethylene glycol. These sintered particles in the substrate could be seen after lifting the thin film of deposition from the glass.P22:P23
“Dendrites in a Battery”
Rong kou, Faculty, Materials Science and Engineering
Artist’s Perspective: Light like a feather and delicate like a fern? Do not let the looks fool you. These metal dendrites grown from battery cycling will penetrate the separator, short-circuit the battery, and cause the battery to overheat and, in some instances, catch on fire. This image inspires me because of the soft, delicate appearance in contrast to the material’s stiff nature, a candy to eyes but a poison to batteries.
Scientific Process: The branched-tree-like dendrites grow in metal batteries such as Lithium batteries and Zinc batteries due to the irregular nucleation and deposition of the metal anodes during the charging/discharging of batteries. The dendrites sprout across the electrolyte and penetrate the separator to short-circuit the batteries causing the failure of the metal batteries. The image shows the microstructure of the Zinc dendrites grown in a Zinc battery.
“Newly deposited cellulose of primary cell wall”
Liza Wilson, Biology
Artist’s Perspective: The primary cell walls in higher plants are an intricate network of cellulose, pectins, and other polysaccharides that provide a rigid support to stand upright, yet it becomes flexible when the plant is growing. The motivation behind this image is to capture how the cellulose is orientated in the wall using a non-destructive, native-condition imaging technique known as Atomic Force Microscopy (AFM). This imaging technique allows one to capture features as small as 2 nanometers in diameter, well below the resolution of confocal microscopy. My goals with this technique are to understand how the different components of the wall are formed and how they interact with each other. This image shows how intertwined the layers of cellulose are in the wall and how these patterns can allow for ‘movement’ of the wall to allow growth. I hope that when viewers see this image, they are curious about the plants around them, and want to learn more about how they are built and how they grow.
Scientific Process: Atomic Force Microscopy image of newest layer of cellulose in a primary cell wall from the outer epidermal cell layer of an onion scale
“Strength in Numbers: Cellulose Bundling in Plant Secondary Cell Walls Reinforces Individual Cells”
Sarah Pfaff, Graduate Student, Biology
Artist’s Perspective: I chose this novel snapshot of cell wall formation because it depicts the bundling of cellulose in the plant secondary cell wall in a very palpable way. The formation of secondary cell walls is what allows plants to grow vertically. In this atomic force microscopy scan, the secondary cell wall bundles are evocative of tree trunks that grow upwards and then branch outwards. This web of cellulose bundles provides strength on the microscale in a way that mirrors the structure that they ultimately support on the macroscale.
Scientific Process: An atomic force microscopy scan of a thin-sectioned plant cell reveals the distinct differences in primary and secondary plant cell wall growth behaviors. When viewed in cross-section the primary cell wall exhibits an even texture (bottom of photo). The secondary cell wall is characterized by cellulose bundles that protrude from the primary cell wall into the cell’s center (top of photo). The bundling of cellulose microfibrils provides mechanical reinforcement to secondary cell walls, conferring rigidity to the plant’s stem. The regeneration of these two types of cell walls is being investigated in free-floating plant cell cultures, providing a new platform for studies of wall development.
“Different facets of unearthed carbides”
Selday Nayir, Postdoctoral Scholar, Materials Science and Engineering
Artist’s Perspective: Carbides are hiding away from the melting pit and plotting a scheme to escape.
Scientific Process: Additively manufactured Inconel 718 build was heat-treated at 1150C for half an hour and quenched. Then, the sample is etched with Lucas’s reagent that selectively etches away the matrix gamma phase while leaving behind the carbides along grain boundaries. The image was taken at Scanning electron microscopy using Apreo at 100 000x magnification
“Converting cost-effective polyacrylonitrile/poly(p-phenylene-2,6-benzobisoxazole) blend precursors to carbon fibers”
Qian Mao, Postdoctoral Scholar, Mechanical Engineering
Artist’s Perspective: The traditional approach of producing polyacrylonitrile (PAN)-derived carbon fibers (CFs) is expensive, partially due to the rigorous control over the sequence of thermal treatments such as oxidative stabilization, carbonization, and graphitization. To this end, we propose the PAN/poly(p-phenylene-2,6-benzobisoxazole) (PBO) blend as a cost-effective CF precursor. And through our ReaxFF molecular dynamics (MD) simulations, we identify that PAN/PBO blends could be a promising alternative for PAN-based precursors, for they can decrease the total cost of CF production by eliminating oxidation process, having a relatively fast conversion rate, and having considerable all-carbon ring formation, comparable to that of oxidized PAN precursor. Based on this finding, a VMD image is made as to describing the process of converting a PAN/PBO blend precursor to clusters of all-carbon ring structures, followed by graphitic 3D or graphene-like 2D structures as the temperature is sufficiently high.
Scientific Process: This VMD image is made by assembling initial PAN and PBO molecular chains, equilibrated PAN/PBO blend system at 300K, clusters of all-carbon ring structures together with the representative oxygen-containing gases and nitrogen-containing groups at 2800K, and graphene-like 2D structures at ultra-high temperature for artistic liberty. The all-carbon ring structures are replicated with periodic boundary condition, slightly overlapping with the graphene-like 2D structures, which can be considered as the formation of graphitic 3D networks and the inception of the growth of graphene-like 2D structures. The coordinates of all atoms are extracted from ReaxFF MD simulations, and the Tachyon render method is applied for generating the image with better visual effect.
“Manifold of self-assembled nanostructures for a model copolymer obtained by unsupervised machine learning”
Wes Reinhart, Faculty, Materials Science and Engineering
Artist’s Perspective: The data and rendering were created using all open-source tools: simulations in HOOMD-blue, data analysis in Python, and rendering in Blender. The colors and arrangements of particles were all computed automatically through molecular dynamics and the UMAP algorithm. The colors of particles communicate the local structure in the material while arrangements of simulation snapshots communicate global trends in the structural phase space. The act of generating this image therefore provides scientific insight on its own, by conveying (nearly) all possible nanostructures that can be self-assembled by this model copolymer under certain constraints. Rather than seeking a logical arrangement or interpretation of all these many simulations, automated workflows provide quantitative understanding of relationships between data. In turn, these workflows allow me to tackle extremely large design spaces and volumes of simulation data by reducing the data down to only a few key parameters.
Scientific Process: Copolymers are known to self-assemble into many interesting nanostructures depending on their chemical sequence and processing conditions. Here, molecular dynamics simulations are used to study self-assembly in a model copolymer for over one thousand different monomer sequences for coarse-grained chains with 20 monomers. The local atomic environment of each monomer is characterized by unsupervised machine learning and colored accordingly. Then each simulation snapshot is embedded in a low-dimensional space using non-linear manifold learning to quantify their relationships to each other. This image is a rendering of over one thousand simulation snapshots, comprised of over one million monomers, with each nanostructure placed in the appropriate location in the learned manifold. Observe the smooth gradient in colors and structures across the image, with micelles at the bottom, liquid droplets in the top right, and strings and membranes in the top left.
“Electrochemical charging near a pseudocapacitive electrode surface”
James Goff, Graduate Student, Materials Science and Engineering
Artist’s Perspective: With the growing needs for cleaner energy storage and conversion, realistic models of energy storage materials are needed to aid in the design of high-performance energy storage devices. Specifically, there is a need for high-power devices for use in electric/fuel cell vehicles. First-principles calculations with continuum solvent models allow us to model these materials systems in realistic conditions. The system pictured is a Ti3C2O2 pseudocapacitive electrode, suitable for high-power transportation applications. As the electrode charges, the response of the ions in the solvent, shown as colored contours above and below the electrode surface, is related to the capacitance of the electrode.
Scientific Process: In order to predict the energy storage capabilities of pseudocapacitive MXene electrodes, the adsorption of ions must be modeled in realistic conditions. The ion adsorption isotherms as a function of voltage are calculated with electronic structure calculations that incorporate the key effects of applied voltage, surface electrification, and the electrochemical double layer. Along with charge stored by chemical reactions, the accumulation of ions in the solvent near the electrode also contributes to charge storage. This is electrochemical double layer charging (colored isocontours in the image) and is accounted for with quantum continuum models during simulations of ion adsorption. After accounting for the different charge storage mechanisms, overall material performance is assessed, and the trends used to design new pseudocapacitor systems.
“Scanning electron micrograph of an etiolated Arabidopsis seedling”
Yunzhen Zheng, Faculty, Biology
Artist’s Perspective: A scanning electron micrograph of an etiolated Arabidopsis seedling (grayscale) growing in the darkness, just after it has shed its seed coat (orange). This electron micrograph is superimposed on a photograph of protein conjugated nano-gold labeled on peeled Arabidopsis seedings epidermal cell wall. This is the moment right before it would break free from the earth and reach toward the sunshine.
Scientific Process: The Arabidopsis seedling grows in darkness for 3 days then put in 100% ethanol for 30 minutes, and critical-point dried after that, followed by iridium coating.
“The Silver Albacore”
Susana Ogozaly, Graduate Student, Chemistry
Artist’s Perspective: A fun part of any cloudy day is always looking in the sky and trying to find figures in the clouds with friends. I compare the nanocubes I synthesize to looking at cloud formations; If you look long enough, you can see something fun in every single sample. The image was created with silver nanocubes, capped with polyvinylpyrrolidone on a silica wafer.
Scientific Process: This SEM image taken using an SE2 detector shows a monolayer of silver nanocubes exposing (1 0 0) facets that were formed from a heated solution of polymer, silver nitrate, and acid in polyol solvent over the course of 28 hours. Excess materials and solvent were removed with ethanol washes, which evaporate to leave the nanocubes to form clusters of cubes, which in this case resemble a fish or shark. These cubes can be transformed further or used for their catalytic properties.
“PAC-MAN formation in two-dimensional (2D) materials”
Leixin Miao and Saiphaneendra Bachu
Artist’s Perspective: Crystal symmetry and surface energies of various atomic planes reveal a lot about a material. They control the kinetics of the material formation as well as dictate the properties of resulting material. Here, we are looking at heterostructures formed by MoS2 and ReS2 with distinct shaped interfaces. To image them, we use high angle annual dark field imaging technique (HAADF) which relies on the atomic number difference between Mo and Re to distinguish them. Also, for the imaging, we transfer the film to a holey carbon support. As a combined result of crystal shapes of MoS2 and ReS2, HAADF contrast and the holey carbon support, the material exhibits this intriguing morphology. It immediately reminded us of the Pac-Man game we used to play in our childhood. With the use of false coloring, we fondly reimagined the Pac-Man gameboard in this image.
Scientific Process: The image shows the intertwined nature of the growth of MoS2 and ReS2 during the heterostructure formation using chemical vapor deposition (CVD) process. Later, the as-grown heterostructure film is transferred to a holey carbon support to image in a scanning transmission electron microscope (STEM). The image was taken using FEI Titan TEM at MCL in high angle annular dark field (HAADF) mode.
“Forest fire in two-dimensional (2D) materials”
Saiphaneendra Bachu, Graduate Student, Materials Science and Engineering
Artist’s Perspective: Atomic edge sites in two-dimensional (2D) materials are energetically different from the rest of the material because of the absence of bonding with some of the neighboring atoms. We call them dangling bonds. And, these act as nucleation centers when a second 2D material is grown subsequently to form heterostructures. Here, we see a zigzag line in the middle of the image which signifies the interface between two 2D materials: MoS2 on the left and ReS2 on the right. This is a result of growth of ReS2 from the edge of MoS2. False coloring of the image highlights the morphology difference between MoS2 and ReS2. While MoS2 is continuous, ReS2 is defective. These defects in ReS2 show up as green patches and hence make the image look like a forest fire that is advancing. The interface between the two materials is showing up as the edge of the forest.
Scientific Process: The image shows the interface between MoS2 and ReS2 in the heterostructures formed by them. The heterostructures are prepared using chemical vapor deposition (CVD) technique. While the growth conditions allowed for defect free growth of MoS2, as-grown ReS2 is defective. This structure is characterized using a scanning transmission electron microscope (STEM) in high angle annular dark field (HAADF) mode. This method replies on atomic number difference Mo and Re to create contrast between MoS2 and ReS2. FEI Titan TEM instrument at MCL was used to acquire this image.
“When Two-dimensional Materials form Voronoi Tessellations”
Amritanand Sebastian, Graduate Student, Materials Science and Engineering
Artist’s Perspective: Is that an aerial snapshot of a lush green paddy field? Or just one close-up look at that solo green leaf? But no, it’s the molybdenum disulfide flakes forming striking asymmetrical patterns. Behold Voronoi tessellation my science cohorts; revel in mathematics coalescing with nature. Merely scout around a bit, and you shall see this intriguing pattern on that picture of a giraffe, on the veins of a dragonfly, the shell of a turtle, a dry desert, and on goes the list.
Scientific Process: Liquid-phase exfoliated molybdenum disulfide (MoS2) flakes forming Voronoi Tessellations. The image is captured with an optical microscope. Ink with MoS2 flakes (< 400 nm in size) dispersed in ethanol is spin coated on an alumina substrate. After spin coating, the substrate is annealed at 400 ˚C in Ar/H2 for 3 hours to evaporate ethanol. This leaves behind MoS2 flakes which forms Voronoi Tessellations.
