MRS Bulletin Materials News Podcast

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Henry Quansah Afful, a postdoctoral research associate at the University of Illinois at Urbana-Champaign about a general framework for understanding how layered materials respond to stress. Afful is interested in the threshold conditions where the material goes from plastic deformation to fracture. Using nanoindentation, his group could learn, at the atomic scale, when plastic deformation starts and how various temperatures affect the mechanical behavior of layered materials. This work was published in a recent issue of Communications Materials.

In this podcast episode, MRS Bulletin’s Laura Leay interviews assistant professor Christos Athanasiou and postdoctoral researcher Danqi Sun from Georgia Institute of Technology about their research on introducing a new material state through polymer necking. After applying different strain rates to poly(ethylene terephthalate) (PET) then testing the material at different orientations, they discovered changes in mechanical behavior. They attributed these behaviors to changes in the microstructure. This work was published in a recent issue of the Journal of the Mechanics and Physics of Solids.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Matt Dickerson of the Air Force Research Laboratory about his research group’s development of 3D- printed nanofibrous ceramics. By blending together block copolymers and pre-ceramic polymers, then burning away the block polymer, the pre-ceramic material transforms into ceramic. Dickerson believes this technique will make large-scale ceramic components easier to make. This work was published in a recent issue of npj Advanced Manufacturing.

In this podcast episode, MRS Bulletin's Laura Leay interviews Carlos Portela from the Massachusetts Institute of Technology about his research group’s design and modeling framework for 3D woven metamaterials. The design framework utilizes a graph structure which allows the woven architecture to be tuned, and it is computationally inexpensive so that it can run on a desktop computer. The outputs include files for finite element modeling to test the metamaterial for large deformations, and for 3D printing of the structure. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Gideon Segev from Tel Aviv University in Israel and Lawrence Berkeley National Laboratory and Shane Ardo from the University of California, Irvine about their ratchet-based ion pumps (RBIPs). Consisting of a nanoporous capacitor-like structure, the RBIP drives a flux of charged particles at voltages as low as 50 mV, while redox reactions need at least 1.23 V. Furthermore, the ratchet is selective where ions can be sorted based on their diffusion coefficient. This opens doors for efficient devices for desalination and selective ion separation. This work was published in a recent issue of Nature Materials. 

In this podcast episode, MRS Bulletin’s Laura Leay reports on the quantified relationship between rheology of a granular biomaterial and tissue self-organization, a study conducted by research groups at the University of California, the Chan Zuckerberg Biohub in San Francisco, Stanford University, and Cedars-Sinai in Los Angeles. The collaborators developed a 3D-bioprinter with a piezoelectric print head to control mechanical forces and a composite extracellular matrix for the biomaterial. One aim of the research was to demonstrate a print medium that could be used to produce a wide variety of biological structures. This work was published in a recent issue of Nature Materials. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Samual Stupp from Northwestern University about his group’s research on developing treatments for spinal cord injuries by use of an organoid. The researchers fabricated the human spinal cord organoid by including microglial cells, which are the immune cells in the central nervous system. They mimicked various kinds of spinal injuries, then applied different injury treatments to see how the organoid responded best. This work was published in a recent issue of Nature Biomedical Engineering.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Barry Rand and his graduate student Tuo Hu at Princeton University about their research on how perovskites interact with metals. For their device, the researchers made a sandwich of gold and indium tin oxide with the perovskite methylammonium lead triiodide in the middle. The charges in their device move two to three orders of magnitude slower than charges in a solid-state electrolyte battery, leading the researchers to draw parallels between the two types of devices. This work was published in a recent issue of Energy and Environmental Science.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Kunli Xiong from Uppsala University in Sweden about his development of metapixels as small as 560 nm, conducive for small video displays that can be located close to the human eye. Instead of using emissive pixels, Xiong uses electronic paper made up of tungsten trioxide nanodisks. By tuning the diameter and spacing of the nanodisks, certain wavelengths of light can be selectively reflected, leading to a color display. The degree of light reflection can be modulated by making use of the material’s electrochromic properties. This work was published in a recent issue of Nature. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Jing Li at Rutgers University and Kun Zhu at the Max Planck Institute of Microstructure Physics about the material and a solution-based manufacturing process they introduced to produce deep blue light-emitting diodes (LEDs). The LEDs emit light at 460 nm. The LED consists of several layers, beginning with an indium tin oxide (ITO) substrate that serves as an electrode. Above the ITO is a single molecular layer of the polymer, polymethyl methacrylate. An 85-nm layer of the emissive hybrid copper iodide material goes on top of the polymer, which forms hydrogen bonds with the emissive material. These hydrogen bonds serve two purposes. They make the hybrid material less reactive, which improves the LED’s stability. The hydrogen bonds also help introduce electrons and holes in balanced numbers into the emissive material, allowing it to emit light more efficiently. This dual hydrogen bonding approach is unique to the researchers’ process. This work was published in Nature.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Jingshan Du from Pacific Northwest National Laboratory about his group’s high-resolution characterization of ice formation. Freezing liquid water between amorphous carbon membranes into single-crystalline ice enabled high-resolution transmission electron microscope imaging. The carbon membranes protected the ice from sublimation in the high vacuum. It was also a good electric conductor, which helped reduce charge buildup on the ice. Charge buildup can cause additional damage to the crystal. From the images they took, the researchers discovered how ice remains stable even with defects such as skewed crystal structure. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Harry Schrickx and Brendan O’Connor from North Carolina State University about their proof-of-concept for a miniaturized spectrometer. With the use of organic components, the spectrometer has a low-power requirement and is sensitive to wavelengths ranging from ultraviolet to near infrared. A unique feature of the design is back-to-back diodes. The research group uses a reconstruction algorithm to determine the spectrum of the incident light, having first been trained using known wavelengths of monochromatic light. The algorithm accounts for noise and instability in the final solution to produce the spectrum. This work was published in a recent issue of Device.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Nitin Padture, who is the Otis E. Randall University Professor and the founding Director of the Initiative for Sustainable Energy at Brown University, about his group’s work uncovering the cracks in a substrate that was coated with a transparent-conducting oxide thin film. This cracking, they discovered, contributes toward the degradation in the electronic properties of devices. The group’s next step was to mitigate the cracking. This work was published in a recent issue of NPJ Flexible Electronics.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Mischa Bonn, director of the Max Planck Institute for Polymer Research in Germany and Dr. Yongkang Wang, group leader affiliated with the Max Planck Institute for Polymer Research as well as Southeast University in Nanjing, China about their research on nanoconfined water. The researchers determined that interfacial rather than nanoconfinement effects govern water structure at the eight Ångstrom level. At five Ångstroms, nanoconfinement effects start to appear with the water molecules starting to lie flat, parallel to the interfaces, and the hydrogen bonding network beginning to weaken. The results may lead to a better understanding of nanofluidic devices, and have implications for desalination, water purification, and hydrogen generation.This work was published in a recent issue of Nature Communications. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Anoop Krishnan from the Indian Institute of Technology in New Delhi, India, about a machine learning model developed after a two-year period of collecting data from the cement industry, supported by the Cement and Concrete Research Network. Krishnan’s work resulted in a model that predicts the alite, belite, and ferrite content in the clinker produced by a given cement plant. These phases control cement quality and give strength to the cement over different curing times. This work was published in a recent issue of Communications Engineering.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Christos Athanasiou from the Georgia Institute of Technology about their approach to the recycling problem from a mechanics-materials perspective. Current recycling approaches can lead to a product with variable properties, which is undesirable. Through a bio-inspired design, Athanasiou’s group built a structure similar to bricks and mortar where the bricks, measuring a few centimeters across, are made from recycled plastic and held together by virgin material, leading to a recycled content of 70%. The stiffness variability was reduced by around 90% compared to using only recycled plastic. This work was published in a recent issue of the Proceedings of the National Academy of Sciences. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Bharat Gwalani from North Carolina State University and Mert Efe from Pacific Northwest National Laboratory about their single-step, energy-efficient method for making a samarium cobalt magnet. Using a process they call “friction stir consolidation,” the researchers apply heat and pressure simultaneously to fuse the two powders together. Their method results in low porosity to make a magnetically stronger, higher quality material than that made by using the conventional method. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Yaroslava Yingling and Joseph Tracy from North Carolina State University about their study on iron oxide colloidal nanoparticles (NPs) coated in oleylamine ligands. By combining experimental work with molecular simulations, their research group determined how to optimize ethanol solvent-mediated ligand stripping in order to control the functionality of the NPs. This work was published in a recent issue of Advanced Materials Interfaces.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Thomas White from the University of Nevada, Reno, about his research group’s work on superheating gold. By hitting the gold foil with 45 femtosecond blue laser pulses, the team heated the foil uniformly up to 14 times hotter than its melting point while maintaining the material’s crystal structure. To confirm the temperature, the group introduced a thermometry technique that derives the temperature based on the velocity of the atoms in the sample. By studying these forms of matter up close in the laboratory, White seeks to better understand what goes on inside planets, stars, and even extreme human-engineered environments, such as nuclear fusion reactors. Furthermore, these experimental results could open new theoretical investigations into superheating. This work was published in a recent issue of Nature.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Sathvik Iyengar, a PhD candidate at Rice University, about the development of a hybrid material called “glaphene.” A hybrid of graphene and two-dimensional (2D) silica glass, glaphene is a semiconductor with a bandgap of ~4 eV. More importantly, Iyengar and colleagues introduce a new method of bandgap engineering using hybrid materials instead of doping, which opens new possibilities for producing electronic components. This work was published in a recent issue of Advanced Materials. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Victor Lopez-Richard from Federal University of São Carlos in Brazil about his memory device called a mem-emitter. Unlike a memresistor (short for “memory resistor”), which made of materials whose electrical resistance can be tuned, the mem-emitter is used to tune optical properties. Experimentally, Lopez-Richard’s research group made the device out of molybdenum diselenide, which is a transition metal dichalcogenide, that was then layered onto a dielectric known as a clinochlore. The researchers found that they were able to tune the intensity of the light emitted according to theoretical predictions. This work was published in a recent issue of Nano Letters.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Ashley Bucsek from the University of Michigan, Ann Arbor about her laboratory-scale three-dimensional (3D) x-ray diffraction (XRD) microscope to replace studies done in synchrotron facilities. A key element of the design is the material used to make the x-rays. Instead of using a solid metal as a target, Bucsek’s research group used a liquid metal source to generate the x-rays, thereby circumventing melting. Among the advantages of miniaturizing the microscope are its immediate availability and the possibility of conducting long-term studies. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Daniel Garcia-Gonzalez from Universidad Carlos III de Madrid in Spain about his research group’s reprogrammable metamaterial. The researchers use a soft polymer, mixed with magnetic particles. By rotating the orientation of the magnets, they tune the softness or compressibility of the material. This work was published in a recent issue of Advanced Materials. 

To enable future lunar settlements, researchers are pursuing ways to construct needed devices on the moon to save the expense of shipping them from Earth. In this podcast episode, MRS Bulletin’s Laura Leay interviews Felix Lang from the University of Potsdam, Germany about his group’s development of perovskite solar cells that utilize the moon’s regolith for the substrate. The researchers achieved power conversion efficiency of ~10%, with some device architectures leading to improved efficiencies of ~12%. Calculations show that using resources from the moon resulted in a power-to-weight ratio that outclassed other technologies, even with the low efficiency. Future work will look to improve this efficiency by considering tandem solar cells. This study was published in a recent issue of Device.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Sheng Xu from Tohoku University, Japan about his lightweight shape memory alloy that retains superelasticity at temperatures as cold as 4 K and as hot as 400°C. This range is about 5 times wider than commercial shape memory alloys. Shape memory alloys are needed for extreme environments such as part of machines in space or deep sea. Xu also sees uses for biomedical applications or for storage containers for liquid fuels like liquid hydrogen, which must be kept at very cold temperatures. This work was published in a recent issue of Nature.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Hang Zhang from Aalto University in Finland about his group’s creation of a composite material that is both stiff and self-healing. The composite involves a hydrogel where the long polymer chains are confined between nanosheets of synthetic hectorite. This material mimics skin that is both stiff and self-healing. Applications may be forthcoming in self-healing soft robots or artificial tissues that can self-heal like synthetic skin. This work was published in a recent issue of Nature Materials. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Lane Martin from Rice University about characterization of relaxor ferroelectrics, materials with noteworthy energy-conversion properties used in sensors and actuators. Martin’s research team investigated the material’s behavior at the nanoscale. The researchers found that the specific thin film they studied—the alloy lead magnesium niobate lead titanate—exhibited excellent properties down to 25–30 nm thick before they would start to shift. This work was published in a recent issue of Nature Nanotechnology.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Beth Dickey from Carnegie Mellon University about her new approach to inducing ferroelectricity into a material. Dickey’s research group worked with a class of materials known as wurtzites. The researchers specifically studied aluminum nitride and zinc oxide, which are not ferroelectric in their pristine form at room temperature. However, alloys of these materials are ferroelectric. When the researchers stacked the ferroelectric alloy with a non-ferroelectric wurtzite and applied electric fields to the material, they found that the crystal lattice of the ferroelectric layer began to invert, then switching propagated into the pristine wurtzite, confirming that the entire material was ferroelectric. The results of this study could lead to development of ferroelectric materials for computers where memory and computation can be brought together into a single device, saving energy. This work was published in a recent issue of Nature. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Harry Atwater from the California Institute of Technology about his study on lightsail propulsion in order to understand how the device can be developed to do fly-by space travel riding a beam of laser light. Atwater’s research group made a square prototype device where the researchers incorporated springs at each corner, etched out of a single sheet of silicon nitride, fastening it to the support frame. They tested its behavior in a two-beam interferometry experiment. Their comprehensive analysis provides a thorough understanding of key parameters that are essential for lightsail propulsion and paves the way for the next step of research: untethered flight. This work was published in a recent issue of Nature Photonics.  

In this podcast episode, MRS Bulletin’s Laura Leay interviews Ashwin Shahani and Alan Taub from the University of Michigan about their group’s simulations and experimental work detailing the formation mechanisms, morphologies, and microstructures of an in situ Al/TiC metal matrix nanocomposites processed via salt flux reaction. Using these insights, the microstructure of a material can be tuned in order to optimize the materials properties. While the three-dimensional imaging is critical to gaining insight into the structure, computational models can facilitate this optimization. This work was published in a recent issue of Acta Materialia. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Xingchen Ye of Indiana University about his research group’s studies on the fundamental behavior of colloidal materials. Colloidal materials consist of liquids with nanoparticles suspended in them. Ye’s team is interested in how a colloidal material’s properties change as the team spatially rearranges the nanoparticles in the liquid. They looked specifically at the self-assembly of gold nanocubes into a lattice structure. Ye’s team studied how that structure gives rise to the material’s bulk properties. This work was published in a recent issue of Nature Chemical Engineering.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Fabian Meder from the Italian Institute of Technology in Genova and the Sant’Anna School of Advanced Studies in Piza, Italy about his research group’s device that makes use of wind-driven plant leaf motion to generate electricity which can power a chemical delivery system. Their triboelectric nanogenerator involves an artificial leaf made of a 500 μm silicone elastomer layer and an electrode made from indium tin oxide. This is attached to the leaf of a plant. A gold-coated pin electrode inserted in the stem of the plant harvests charges from the plant tissue. This work was published in a recent issue of Bioinspiration & Biomimetic. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Bowen Deng, a graduate student in Gerbrand Ceder’s group at the University of California, Berkeley, about their work on increasing the accuracy of artificial intelligence/machine learning materials prediction models. The use of computer simulations to predict the interaction between atoms in a given molecule is being replaced by machine learning. Researchers describe the atoms’ collective interactions as a quantity of energy, where higher energies correspond to stronger forces holding the molecule together. Now, Deng’s research group studied three machine learning models and found that they tend to predict lower energies than what is accurate by about 20 percent. The researchers have determined that these underpredictions were caused by biased training data and they found a way to remedy the situation. This work was published in a recent issue of NPJ Computational Materials.

In this podcast episode, MRS Bulletin’s Laura Leay interviews David Cahen from the Weizmann Institute of Science, Israel, about the impact surface defects have on bulk properties, specifically in the case of lead halide perovskites. In a perspective he co-authored, Cahen connected numerous experimental data from other researchers that exposed this phenomenon. By understanding how surface defects control the material’s electronic behavior, researchers can pursue new materials for the development of long-lasting devices. This work was published in a recent issue of Advanced Materials. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Gwangmin Bae of Korea University about his work with colleagues on the design of a new smart window system that utilizes compression. Like other smart windows, this window makes use of pores within the material to adjust its transparency. However, instead of using a stretchy material that controls light scattering through the pores, Bae and colleagues used a material that compresses in thickness. That is, the window becomes more transparent when it is compressed. The researchers place this structured porous material made of the polymer polydimethylsiloxane or PDMS between two panes of glass to create the smart window. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Leif Asp of Chalmers University of Technology about his group’s development of an all-carbon fiber-based structural battery. The negative electrode uses carbon fiber and, for the positive electrode, the carbon fiber is coated with lithium iron phosphate. In both cases the carbon fiber takes on the roles of mechanical reinforcement and current collection. This work was published in a recent issue of Advanced Materials.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Nancy Sottos, the Maybelle Leland Swanlund Endowed Chair and head of the Department of Materials Science and Engineering at the University of Illinois–Urbana Champaign (UIUC), and Justine Paul, a former student at UIUC who now holds a position at DuPont, about their work with frontal polymerization. By mimicking patterns in biological materials such as shells, their research group took a multidisciplinary approach to control crystalline patterning, which ultimately enabled them to control mechanical properties of polymers. By applying heat, they made slight changes in the chemical reactions to achieve specific crystalline patterns. This work was published in a recent issue of Nature.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Reza Moini of Princeton University about his group’s development of an enhanced additive manufacturing technique to fabricate cementitious materials with excellent fracture toughness. They based their design of the material on the double-helical or double-bouligand structure of coelacanth fish scales that resist deformation. In order to fabricate the material, Moini’s research team used a two-component robotic additive manufacturing process. The extrusion system was controlled using specialist algorithms. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews postdoctoral research fellow Rohit Pratyush Behera and Prof. Hortense Le Ferrand of Nanyang Technological University in Singapore about their design of a strong and tough ceramic that absorbs energy, inspired from biology. They borrowed microscopic designs found in a mollusk, a mantis shrimp, and the enamel casing surrounding human teeth. The researchers stacked round discs of aluminum oxide particles in horizontal layers in a helical structure, then encased the structure in an extra protective layer made of alumina nanoparticles. The aluminum oxide in the discs is designed to respond to an external magnetic field, modifying the orientation of the discs layer by layer, consequently adjusting the properties of the ceramic composites. This work was published in a recent issue of Cell Reports Physical Science.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Yen-Hung Lin of Hong Kong University of Science and Technology about his work to eliminate defects in perovskite solar cells. Lin’s group treated the perovskites with a category of molecules known as amino-silanes, which bind vacancies in the perovskites, preventing recombination of the electrons and holes. The amino-silane treatment retained the device’s performance at 95% power conversion efficiency for more than 1500 hours. This work was published in a recent issue of Science. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Michael Pettes, deputy group leader and staff scientist at the Center for Integrated Nanotechnologies in Los Alamos National laboratory about a characterization technique that employs a four-dimensional scanning transmission electron microscope (4D-STEM) paired with complex computational data analysis to directly measure the thermal expansion coefficient (TEC) of monolayer epitaxial tungsten diselenide. The standard technique for directly measuring the TEC involves X-ray diffraction, but 2D materials are too thin. 4D-STEM uses a patterned electron probe which enables diffraction positions to be accurately mapped in real space. This method overcomes the challenges of indirect measurements and spatial resolution. This work was published in a recent issue of ACS Nano. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Michael Dickey of North Carolina State University about the discovery and mechanical properties of glassy gels. Dicky credits his postdoc Meixiang Wang who, while studying ionic liquids, created the first glassy gel. Dicky’s group found that the mechanical properties of their glassy gel include shape memory, self-healing, and adhesion. While other materials may demonstrate comparable toughness and stretchiness, the glassy gel offers an advantage because of its simple curing process. This work was published in a recent issue of Nature. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Coskun Kocabas from The University of Manchester in the UK about his development of a metamaterial that can tailor thermal emission. Rather than using a periodic system, which most topological materials employ, his research team borrowed a concept from laser design and created an optical cavity using a dielectric medium sandwiched between two layers that act as mirrors: a metal substrate and a top layer of platinum. The top layer serves as a thermal emitter, and the thickness of the top layer defines the topological property that regulates thermal emissivity. This work was published in a recent issue of Science. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Rasmus Neilsen from the Technical University of Denmark about his fabrication of a monolithic selenium/silicon tandem solar cell. The selenium forms the top cell of the tandem device, with silicon used as the bottom cell. Selenium-based single-junction solar cells have traditionally used fluorine-doped tin oxide. In this work indium-tin oxide was used as a transparent conductive layer that is easier to deposit and its use is more widespread. Neilsen and his research team controlled the thickness of the carrier-selective contacts in the silicon solar cell that protects the silicon layer from the processes used to deposit subsequent layers on top, thus enabling them to deposit the top cell directly onto the substrate. This work was published in a recent issue of PRX Energy. 

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Mihir Pendharkar of Stanford University about characterizing electronic properties of twistronics materials. Twistronics refers to a type of electronic device consisting of two-dimensional materials layered at a relative twist angle, forming a new periodic structure known as moiré superlattices. Pendharkar and colleagues studied different configurations of graphene layered with hexagonal boron nitride. Determining the twist angle of any particular sample is extremely time-consuming. By developing a characterization technique called torsional force microscopy, Pendharkar and colleagues have reduced the time to a matter of hours. This work was published in a recent issue of Proceedings of the National Academy of Sciences. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Falon Kalutantirige from the University of Illinois Urbana-Champaign and Ying Li from the University of Wisconsin-Madison about their approach and discovery when characterizing nanovoids in polymer films. Using polyamide (PA) membranes as their subject of study, the researchers applied graph theory combined with electron tomography and molecular dynamics simulations to characterize the morphology of the nanovoids. The key to understanding permeance of the membranes lies in understanding the void space that was mapped using electron tomography. Using their mixed-method approach, the researchers were able to relate the nanoscale morphology to membrane function. Taking this beyond the study of PA membranes, the research team showed how nanovoids impact the synthesis‒morphology‒function relationships of complex nanomaterials. This work was published in a recent issue of Nature Communications. 

In this podcast episode, MRS Bulletin’s Laura Leay interviews Alexandre Dmitriev from the University of Gothenburg, Sweden about his group’s computational model of a three-dimensional metamaterial exhibiting a magnetoelectric effect—known as the Tellegen effect—when exposed to light. The building blocks of the metamaterial are comprised of disks of silicon, 150 nm in diameter, supporting a cylinder of cobalt. Silicon is chosen for its high refractive index and cobalt for its magnetic properties. These building blocks are randomly distributed in a host medium such as water or a polymer. The metamaterial has applications in areas such as improving the efficiency of solar cells, creating one-way glass, or improving lasers. It also has the potential to revolutionize how the universe is understood and could hold the key to studying dark matter. This work was published in a recent issue of Nature Communications.

In this podcast episode, MRS Bulletin’s Laura Leay interviews Antonio Dominguez-Alfaro from the University of Cambridge, UK about the development of a single-step manufacturing approach for a multimaterial 3D-printing method. The research team created two inks. One ink is a polymeric deep eutectic solvent – polyDES – made by combining and heating two salts to form a deep eutectic monomer and adding a photo-initiator to allow the ink to be cured. This ink is an ionic conductor so can capture signals from neurons inside a biological system. The other ink was based on the polymer Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which is commonly used in bioelectronics as a mixed electronic and ionic conductor. The work resolves many challenges of applying additive manufacturing in the field of bioelectronics. This work was published in a recent issue of Advanced Science. 

In this podcast episode, MRS Bulletin’s Elizabeth Wilson interviews postdoctoral researcher M. Iqbal Bakti Utama of Northwestern University about a method allowing single photon production without defect. Aryl diazonium chemistry has been used in the past to functionalize the surface of carbon nanotubes. Utama’s group found that this chemistry also works for tungsten diselenide surfaces. The group immersed tungsten diselenide monolayers into an aqueous solution of 4-nitrobenzene-diazonium tetrafluoroborate. The electrophilic molecules withdraws electrons from the monolayer, creating aryl diazonium radicals. These radicals react with each other to form nitrophenyl oligomer chains. Instead of binding covalently to the monolayer surface, the oligomers form an adlayer that is physisorbed on the tungsten diselenide surface. The spectra of photons generated when the research team irradiated the coated surface was vastly simpler than the uncoated monolayer. This work was published in Nature Communications.

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Irmgard Bischofberger of the Massachusetts Institute of Technology about her investigation of how chirality emerges in nature. She uses liquid crystal molecules of disodium chromoglycate in her studies. When the molecules are dissolved in water, they form linear rods. The research group then forces the rods through a microfluidic cell, causing the rods to assemble into spiral structures without mirror symmetry. The achiral structure transformed into a chiral one. What is unique, says Bischofberger, is that the new material is composed of non-chiral building blocks. This work was published in a recent issue of Nature Communications.