Symposium QT06: Defects in Solid-State Materials for Quantum Technologies

David Awschalom, University of Chicago, Argonne National Laboratory

Quantum Spintronics with Silicon Carbide and Oxides

Written by Suman Mondal

Optically active spin defects in semiconductors, vital for quantum computing and sensing, now promises scalable integration with existing technologies. A research team from the University of Chicago and Argonne National Laboratory has pioneered silicon carbide (SiC) and erbium-doped cerium oxide (CeO₂) as platforms for robust, telecom-compatible quantum devices.

In SiC, the neutral divacancy (VV⁰) defect—isolated in optoelectronic devices—exhibits lifetime-limited photon emission and millisecond spin coherence, bolstered by isotopic engineering to minimize nuclear spin noise. “By tailoring the nuclear environment, we’ve extended spin coherence beyond 5 seconds—a milestone for solid-state qubits,” says co-author David Awschalom. The team also engineered vanadium ions in SiC, emitting in the telecom O-band (1,300 nm), which saw a 10,000-fold increase in spin relaxation time at cryogenic temperatures, ideal for fiber-based quantum networks.

Meanwhile, erbium-doped CeO₂ films on silicon substrates achieved 0.66 µs electron spin coherence and 2.5 ms relaxation at 3.6 K, leveraging CeO₂’s nuclear-spin-free lattice. At 77 mK, coherence times approach milliseconds, with on-chip ESR control. Er³+ in CeO₂ combines telecom compatibility with silicon integration—a game-changer for quantum hardware.

Key innovations include electrically tunable spin qubits in SiC heterostructures, Stark-shifted photon emission, and vanadium’s host-agnostic orbital structure for portable quantum nodes. The work bridges quantum defects with CMOS-compatible materials, accelerating scalable quantum networks.

Symposium EL05: 2D and 3D Printed Optoelectronics and Sensors—Advanced Materials, Device Functionality and Systems

Juan Cisneros Barba, University of Colorado Boulder

Distributable Screen-Printed Soil pH Sensor Shows Long Term Invariant Data Acquisition Across Soil Moisture, Compaction Levels and Soil Types

Written by Corrisa Heyes

PhD student Juan Cisneros Barba presents a promising solution for long-term, in-field soil pH monitoring. Soil pH is critical for nutrient availability, microbial activity, and overall plant health, but most commercial pH sensors are costly, short-lived, or unsuitable for continuous field deployment. The research team at UC Boulder have developed a screen-printed, flexible soil pH sensor, using a carbon-alizarin composite as the active sensing material and a PVB-NaCl membrane for reference electrode protection. These design choices enable the sensor to operate directly in soil, without requiring slurries or pre-treatment, and to deliver consistent data under varying moisture levels, compaction conditions, and soil types. The sensor shows a strong, stable response across a range of gravimetric water contents (≥20%), performs reliably in compacted soils, and is able to track pH changes long term (over one week) without human intervention/recalibration. It can achieve an R² > 99% in soil type comparisons and R² ~80% against commercial probes over extended operation. This low-cost, distributable platform enables scalable deployment to generate high-resolution pH heatmaps, making it a valuable tool for sustainable agriculture and data-driven land management.

Symposium CH02: Emerging Optoelectronic and Quantum Materials—Advanced Multimodal Characterizations

Xiaoyang Zhu, Columbia University

Ferromagnetic 2D vdW Semiconductors

Written by Md Afzalur Rab

Xiaoyang Zhu presented his group's research on two-dimensional van der Waals materials with multifunctional properties, focusing on semiconductors that exhibit magnetic and ferroelectric behaviors. The team explored how various physical phenomena, such as magnetism and electric polarization, interact in a coupled manner to enable new mechanisms for control and sensing at the nanoscale. Their work contributes to the broader field of quantum materials and offers insights into novel ways to manipulate these properties for advanced applications. This research is particularly relevant for emerging technologies in areas such as sensing, data storage, and wireless communication.

In their investigation of the magnetic semiconductor CrSBr, the team discovered a strong interaction between excitons—electron–hole pairs—and magnetic order, leading to magneto-exciton coupling. This coupling allowed for the detection of magnons, or spin waves, at extremely low energy ranges using optical techniques. Similarly, in the ferroelectric material NbOI₂, the researchers observed a large optical rectification effect, which enables the material to convert light into terahertz radiation more efficiently than conventional materials. They also identified an unusual coupling between transverse optical phonons and excitons, contrasting with typical longitudinal optical phonon behavior. These findings, enabled by advanced ultrafast optical methods, reveal new possibilities for manipulating low-energy quantum excitations, advancing the design of multifunctional materials with complex, tunable responses to external stimuli.

Symposium EL05: 2D and 3D Printed Optoelectronics and Sensors—Advanced Materials, Device Functionality and Systems Sustainable Liquid-Phase Production of Janan Hui, Northwestern University

Janan Hui, Northwestern University

Cellulose-Derived Graphene for Printable Agricultural Monitoring Devices

Written by Corrisa Heyes

PhD student Janan Hui presents a sustainable approach to manufacturing biomass-derived graphene for use in low-cost, printed environmental sensors, with a focus on agricultural monitoring. Conventional graphene production often relies on mined graphite and synthetic exfoliating agents, which are energy-intensive, environmentally damaging, and incompatible with biodegradable device fabrication. Hui’s work offers an eco-friendly alternative that uses hardwood-derived biochar and cellulose nanocrystals (CNCs) as feedstocks for liquid-phase exfoliation (LPE). The research team developed a fully aqueous exfoliation process using CNCs extracted from Miscanthus X. Giganteus, a perennial grass. This method avoids toxic solvents and results in graphene nanoplatelets with comparable crystallinity and conductivity to those derived from conventional graphite. The exfoliated graphene-CNC composite was then formulated into an aerosol jet printing ink for fabricating humidity sensors on paper substrates made from hemp and miscanthus residues. These fully plant-based sensors detect humidity through a resistance-change mechanism: CNCs swell upon absorbing water, disrupting electron pathways in the graphene network. The devices demonstrated excellent sensitivity (up to 2.6× resistance change across 35–85% relative humidity), long-term cyclability, and thermal stability. This sustainable platform not only minimizes environmental and supply chain impacts but also enables scalable production of printed electronics for smart agriculture and environmental monitoring.

Symposium SB02: Flexible, Stretchable Biointegrated Materials, Devices and Related Mechanics

Philipp Gutruf, University of Arizona

Biosymbiotic Electronics – Chronic Health Insights Beyond Epidermal Turnover Limits

Written by Kwon-Teen Chen

Wearable electronics have a similar flaw, a break in data collection to recharge the device itself because they have a bad retention rate. Philipp Gutruf from the University of Arizona has been working on mitigating this problem to develop a thin film electronics that is able to wirelessly recharge by far field power transfer. The research team developed a black box that would be placed on top of a desk and would fully recharge the sensors across a six hour period, within the average workday. This allowed the researchers to monitor different human body metrics across a day’s entire 24 hours in a two-week span. This continuous monitoring reduces the issues of retention rate and it showed some peaks and dips in electrocardiography (ECG) data that are generally not shown because they are averaged out in other ECG machines. One of the future areas the researchers could continue to explore is the viability over a longer period of time, as well as the degradation of the sensors.

Symposium EL05: 2D and 3D Printed Optoelectronics and Sensors—Advanced Materials, Device Functionality and Systems

Gregory Whiting, University of Colorado Boulder

Printed Sensors for Continuous Monitoring of Soil and Plant Conditions

Written by Corrisa Heyes

Gregory Whiting delivered an invited talk highlighting the use of printed electronics for high-resolution environmental sensing in soils and plants. This approach is aimed at addressing challenges in sustainable agriculture and climate monitoring. Spatially dense, real-time data is vital for optimizing resource use, yet current soil sensing technologies remain too sparse, expensive, or labor-intensive to scale. Whiting’s BEEM Lab at UC Boulder has developed low-cost, printed sensor platforms capable of monitoring soil moisture, pH, ion concentrations (NO₃⁻, NH₄⁺, K⁺), temperature, conductivity, and even microbial activity. Notably, the research group uses biodegradable conductive traces that serve as both sensor and substrate, allowing monitoring of decomposition via resistance changes to infer microbial activity. For ion sensing, the researchers implemented potentiometric electrodes functionalized with alizarin to reduce drift, and combined sensor outputs with artificial neural networks (ANNs) to infer hard-to-measure properties like nitrous oxide (N₂O) emissions. On the plant side, Whiting’s group engineered printed bioelectronic cryogels, which are soft, stable, and biocompatible materials for long-term in vivo sensing. These gel-based electrodes conform to plant tissue and outperform commercial sensors in signal quality and durability. Applications range from whole-sap ion detection to long-duration monitoring of plant-insect interactions, such as in Venus fly traps. Together, these advances showcase how printed electronics and soft materials can unlock scalable, long-term environmental sensing across complex natural systems.

Symposium MT05: The Materials Science of Synthesis Across Scales Through Data Science Integration

Kristen A. Fichthorn, The Pennsylvania State University

Toward Controlling the Morphology in Nanocrystal Growth—Thermodynamic vs Kinetic Shapes

Written by Suman Mondal

Controlling the shape of metal nanocrystals—critical for catalysis, optics, and electronics—has long been hindered by the complex interplay of thermodynamics and kinetics. Kristen Fichthorn’s research team at Penn State has deciphered this puzzle using molecular dynamics (MD) simulations and machine learning (ML), revealing how silver (Ag) and copper (Cu) nanocrystals transition from equilibrium to kinetic shapes during growth.

“Equilibrium shapes aren’t static—they shift with temperature and size, while kinetic effects dominate beyond single-nanometer scales,” says Fichthorn. By simulating growth pathways, her group found that subnanometer crystals adopt equilibrium structures, but as they grow, kinetic processes “freeze” shapes dictated by deposition rates. ML algorithms classified 15+ shape subclasses in Cu, influenced by stacking faults and surface features.

Crucially, solvent environments reshape outcomes: ethylene glycol (EG) promotes {111} facets in Ag, while EG with polyvinylpyrrolidone (PVP) suppresses them. Such insights could tailor nanocrystals for single-atom catalysis or plasmonics. Challenges remain, like refining force fields for gold (Au), but Fichthorn’s work charts a path.

“This isn’t just about predicting shapes—it’s about designing synthesis routes to achieve them,” she says. Her team’s analysis of bimetallic Ag-Cu systems further highlights how composition and temperature tweak morphologies.

By bridging simulations, ML, and experimental data, this research equips chemists to harness kinetics and thermodynamics, transforming nanocrystal design from trial-and-error to precision engineering.

Symposium SF02: Complex Oxide Epitaxial Thin Films

Haiyan Wang, Purdue University

Multifunctional Hybrid Metamaterial Designs Towards Advanced Device Applications

Written by Kwon-Teen Chen

Haiyan Wang from Purdue University works on growing different vertically aligned nanocomposites (VANs) with a focus on understanding their base characteristics, as well as their potential to be implemented into devices. She discussed her research group’s work developing multifunctional VANs with strong anisotropy, some of their potential in memristors, as well as the ability to create free-standing VANs. Her group grows two or more materials at a time in order to unlock some unique functionality in their materials as well as increase the tunability of the VANs physical properties. Her group has also found ways to make VANs that are oxide-oxide, oxide-metal, nitride-metal, and oxide-nitride. In terms of tunability, she has found that a low dielectric pillar and a high dielectric matrix will make a highly anisotropic metamaterial, and vice versa. The researchers have also found that they can tune the magnetic field by controlling the pillars’ structure and density. Her group also tried to grow pillars with gold at the same time; this showed three different types of pillar morphologies and her group is interested in learning more about this processing of the VAN pillars. Further work will be done in developing new thin films and devices.

Symposium EL05: 2D and 3D Printed Optoelectronics and Sensors—Advanced Materials, Device Functionality and Systems

Yanliang Zhang, University of Notre Dame

High-Throughput and Hybrid Printing of Multifunctional Devices for Energy Harvesting and Multimodal Sensing

Written by Corrisa Heyes

Yanliang Zhang presents a suite of high-throughput and hybrid additive manufacturing techniques for fabricating multifunctional devices aimed at energy harvesting, health monitoring, and structural sensing. His laboratory’s approach leverages aerosol-based combinatorial printing and multi-material, multi-scale hybrid printing (HMMP) to create integrated systems that combine structural, electronic, and biological materials in a scalable and autonomous way. The laboratory has developed combinatorial printing strategies for thermoelectric (TE) materials. Instead of printing dozens of samples to test different doping levels, Zhang’s research team prints a single sample with a continuous gradient of compositions, enabling rapid mapping of thermoelectric properties like the Seebeck coefficient and electrical conductivity. Machine learning, specifically Bayesian optimization, is integrated with ultrafast flash sintering to tune processing parameters and reach peak performance in under 30 iterations. Their printed TE films achieve power factors exceeding 2200 µW/mK² at room temperature, which surpasses many commercial materials. Additionally, Zhang introduces strain-insensitive, stretchable electronics based on printed universal gradient interfaces (UGIs). These systems include wearable sensors for temperature, pulse, and oximetry that maintain stable signals even under deformation. Additionally, the laboratory has developed multimodal sensors capable of operating at up to 700°C for aerospace structural health monitoring. By combining top-down print design with bottom-up materials control, Zhang’s platform demonstrates a powerful path forward for rapidly prototyping and optimizing next-generation electronic devices.

What do Materials Scientists Think of Generative AI?

MRS TV hits the floor of the Seattle Summit to ask materials scientists what they think about generative AI's use in the field.