NanoDay!

JOSHUA MCCUNE
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Hydrophilic Reactive Oxygen Species-Degradable Scaffolds for Wound Healing"

We have previously developed a synthetic polythioketal urethane (PTK-UR) wound dressing which degrades in response to reactive oxygen species (ROS) in the wound environment. However, our previous work was limited in the range of achievable hydrophilicity due to the synthetic approach and use of ethylene glycol monomers (EG). Here we have innovated a novel class of PTK materials capable of achieving significantly more hydrophilic wound dressings. These super hydrophilic PTK-URs have been validated to maintain morphological features (pore structure, pore size, and overall porosity) and degradation mechanisms previously optimized with the EG-PTK-URs. Despite comparable physical characteristics, these super hydrophilic scaffolds are more efficient at scavenging ROS, ultimately providing cytoprotection against oxidative stress in vitro. These scaffolds also exhibit larger swell ratios and improved moisture retention, a critical design feature for wound dressings.

KIERAN NEHIL-PUELO
Graduate Student, Interdisciplinary Materials Science
PI: Peter Cummings

"Grouper: Software for Enabling Efficient, Exhaustive Enumeration of Chemical Space Using Algebra and Chemical Groups"

The exploration of chemical space stands as a crucial endeavor across various scientific domains, particularly in the realms of material and drug discovery, where the determination of novel molecules holds paramount importance. However, prevailing methods, especially those reliant on deep learning-based generative models, encounter significant limitations stemming from their inefficient representation of molecules and stochastic nature. These generative methods typically rely on an atomistic graph or sequence-based representations of molecules. Atomistic representations often result in a non-physical and inefficient sampling of the expansive landscape of potential molecular structures. In the field of organic chemistry, the advantageous representation of molecules as combinations of functional groups is well established. In response to the challenges facing previous generation methods, and with the known utility of functional groups, we have devised an open-source software, molGrouper, that uses pre-specified chemical groups as fundamental building blocks for molecular structures. The fundamental data structure of our software is the GroupGraph which represents functional groups in a molecule as nodes, with bonds between groups represented as edges. The key functionalities of Grouper are the exhaustive generation of a complete chemical space, the translation of members of the chemical space to molecular simulation engines, and the conversion of molecular structures into data-efficient machine learnable inputs. molGrouper addresses the aforementioned needs of the expanding cheminformatic industry and provides a general and transferable method to represent the growing space of molecules.

WEIFAN LIU
Graduate Student, Civil and Environmental Engineering
PI: Shihong Lin

"Theory for Ion Transport in Electrochemical Ion Pumping"

Electrochemical ion pumping (EIP) is an innovative electric field-driven separation process that combines the advantages of conventional electrosorption and electrodialysis for effective ion separations. This study presents a comprehensive mathematical model for water desalination utilizing EIP with ion exchange polymer filled porous carbon electrodes. By analyzing dynamic concentration and potential profiles during charging and discharge cycles, the model elucidates ion transport mechanisms and highlights the role of the electrode design in enhancing performance. Experimental verification of the model is conducted through constant current desalination tests, demonstrating a strong correlation between predicted and observed performance metrics. The model not only captures key behaviors of ion distribution and electrode potential dynamics but also lays the groundwork for future extensions to predict full-scale EIP systems across varied operational conditions. This work advances the mechanistic understanding of EIP systems for future sustainable desalination applications and beyond.

TAO HONG
Graduate Student, Interdisciplinary Materials Science
PIs: Deyu Li & Jason Valentine

"Metasurface-assisted Compact Flow Cytometer for Sensing Fluorescence Signals"

Flow cytometer (FC) plays a significant role in clinical and biological research to identify and classify cells based on their optical fluorescence signals. Narrow bandpass filters among other bulky optics have been widely applied in FCs to form spectral channels to detect the presence of specific fluorescence labels. However, the typical usage of FC has been limited in the centralized labs due to its bulky volume and high cost. Our proposed FC system leverages the compactness and designer optical response of metasurfaces to develop miniatured spectral channels that are inversely designed by machine learning to achieve comparable performance than state-of-the-art.

MARIAH BEZOLD
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Hybrid Shear-thinning Hydrogels as an Injectable Delivery Platform for Repair of Diabetic Skin Wounds"

In the inflammatory phase of wound healing, reactive oxygen species (ROS) are produced to fight microorganisms, prevent infection, and promote immune cells. However, hyperglycemia in diabetic wounds impairs this function by sustaining oxidative stress, preventing resolution of inflammation, and blocking the transition to the later stages of wound healing.

The objective of this work was to develop a hybrid shear-thinning hydrogel as a bioresorbable and injectable therapeutic delivery platform which can provide controlled delivery of small molecule PHD2 inhibitors through incorporation of ROS-reactive nanoparticles with the biological polymer, hyaluronic acid (HA), to achieve accelerated repair of chronic diabetic skin wounds.

To investigate the impact of polysulfide chemistry on the antioxidant function of resulting hydrogels, different polysulfide monomers were incorporated into nanoparticles which were mixed with HA to yield polysulfide hydrogels possessing a range of ROS-reactivities.

Evaluation of hydrogels in excisional wounds of diabetic mice identified polysulfide chemistries which resulted in sustained release of small molecule PHD2 inhibitors, reduced levels of oxidative stress and inflammatory macrophages, and possessed potent antioxidant functions. These studies ultimately resulted in the identification of polysulfide hydrogels which demonstrate promise as a therapeutic delivery platform for improving outcomes in chronic diabetic skin wounds.

The following work has not only provided a comprehensive analysis on the structure-function relationship of polysulfide chemistry within the hydrogel system but has also produced an entire library of hydrogels which possess a range of sensitivities to ROS and resulted in the development of a unique platform technology that may be used in additional tissue repair and regeneration applications. 

VIVIAN NWOSU-MADUEKE
Graduate Student, Interdisciplinary Materials Science
PI: Carlos Silvera Batista

"Chemotactic Manipulation of Charged Colloids under Aperiodic Electrodiffusiophoresis"

Under the influence of ac electric field, charged colloidal particles experience long-range forces tunable by the field parameters. This results in dynamic 2D crystal structures that are driven by the interplay between hydrodynamic flows and particle electrostatic interactions. Recently, the integration of low-frequency electric fields with concentration gradients by electrodiffusiophoresis gave rise to the transport, focusing, and assembly of charged colloids a few microns from the electrodes. In this study, our objective is to elucidate the underlying forces governing particle assembly by investigating the particle interactions. Additionally, we seek to explore strategies for manipulating these interactions under more complex conditions. The individual particles appear to experience an attractive force at the focal region, which exhibits a significant dependence on surface chemistry. Insights garnered from these investigations will not only enhance our understanding of AC electrokinetics but also facilitate the precise manipulation of charged colloidal particles within intricate environments.

WILLIAM LOWERY
Graduate Student, Chemistry
PIs: David Cliffel & Kane Jennings

"Protein-Polymer Composite Nanoparticles through the Photopolymerization of Pyrrole by Photosystem I"

Polymers have been shown to be an excellent scaffold for proteins when designing electrochemical systems, particularly for Photosystem I. Utilization of synthetic polymer chemistry has allowed a great deal of tunability within the protein/polymer interface to improve electron transfer from the protein, but most approaches still need to rely on small molecule electron mediators to bring out the finest performance. Seeking to address these issues, a new approach is presented to synthesize Photosystem I/polypyrrole (PSI/PPy) nanoparticles showcasing synergistic photoelectrochemical effects. Extensive electron microscopy characterization is presented of the PSI/PPy composites along with spectroscopic and electrochemical data.

CHRISTOPHER WHITTINGTON
Graduate Student, Interdisciplinary Materials Science
PI: Sharon Weiss

"Antislot Photonic Crystals for Sensing, Communication, and Quantum Platforms"

1D photonic crystal nanobeams (PhCNBs) are periodic dielectric structures designed to manipulate light on chip. Introducing a cavity to the PhCNB creates sharp resonances that can be used for applications including biosensing, optical communication, and quantum information systems. We have shown that engineering deep subwavelength scale features into PhCNBs can drastically modify the mode distribution and significantly enhance the peak energy density and light-matter interactions on this platform. We discuss the desirable properties and applications of the “antislot” PhCNB, which is designed with a deep subwavelength dielectric bar that bisects the circular etched region in each PhC unit cell. The first application we highlight is biosensing, where we have demonstrated increased sensitivity for the detection of proteins using an antislot PhCNB versus a PhCNB without subwavelength-scale engineering. Secondly, we highlight the antislot PhCNB’s potential for creating a low power, ultrafast all-optical modulator for on-chip optical communication using the phase change material VO2. Finally, we highlight the antislot PhCNB’s potential for use in low power, on-chip quantum information systems with the incorporation of single photon light emitters.

AMELIA SOLTES
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Optimization of siRNA Nanoparticles with Custom Polymeric Surfactants"

Small interfering RNA (siRNA) is a promising therapy for specific gene knockdown. Here, siRNA-loaded nanoparticles (si-NPs) are designed and screened for siRNA delivery. The si-NPs are comprised of a core that complexes with the siRNA and enables endosomal escape, as well as a surfactant intended to provide colloidal stability. Custom polymeric surfactants have been developed to anchor to the core, promote gene silencing activity and viability, and enable bioadhesive capabilities. These si-NPs with custom polymeric surfactants show promise as an effective method of gene knockdown with improved activity and toxicity compared to lipid-polyethylene glycol (lipid-PEG).

SK MD ALI ZAKER SHAWON
Graduate Student, Chemical and Biomolecular Engineering
PI: Shihong Lin

"Decoupling the Influence of Sorption and Diffusion on Membrane Permselectivity in Pervaporation"

Membrane-based pervaporation (PV) is a well-established technique for separating azeotropes and close-boiling mixtures. Permselectivity, a crucial performance metric, arises from the combined effects of sorption and diffusion selectivity, typically measured in its entirety from PV experiments. This study, deconvolutes the impact of sorption and diffusion selectivity from overall permselectivity, providing a deeper understanding of membrane performance. We explore the performance of crosslinked polyvinyl alcohol (PVA) membranes in ethanol dehydration using the PV process. Sorption and PV experiments were conducted separately, analyzing swelling, water and ethanol uptake, effective sorption selectivity, and permselectivity across various feed concentrations. The results revealed that swelling is directly proportional to water concentration in the feed, and effective water sorption selectivity is significantly influenced by feed water concentrations. The experimental data indicates that water flux is driven by self-plasticization and is proportional to feed water concentration, whereas ethanol flux is influenced by crossed plasticization, which is affected by the water’s plasticization and transport within the membrane. These findings highlight the importance of understanding sorption and diffusion selectivity independently for efficient separation, offering valuable insights for troubleshooting membranes with poor overall selectivity.

EMMA BARTELSEN
Graduate Student, Interdisciplinary Materials Science
PI: Josh Caldwell

"Multi-resonant Tamm-plasmon-based infrared gas sensor for improved sensitivity and selectivity"

Wavelength-selective thermal emitters provide a cost-effective approach for narrow-band sources in the mid- to long-wave infrared. These emitters have been frequently designed to achieve a desired target emissivity spectra for various applications including thermal camouflage, radiative cooling, and gas sensing. This work will discuss how wavelength-selective thermal emitters can be realized through the use of Tamm plasmon polaritons (TPPs) supported by an aperiodic distributed Bragg reflector (aDBR) for gas sensing applications. The TPP emitter discussed will be composed of an aDBR deposited on a doped cadmium oxide (CdO) film, where layer thicknesses and carrier density are varied to realize a close spectral match to the absorption wavelengths of the target analyte. Through utilizing an aDBR with a tunable plasma frequency CdO film, wafer-scale wavelength-selective emitters can be realized without the use of lithography.

YUSHENG WANG
Graduate Student, Mechanical Engineering
PI: Xiaoguang Dong

"Sensory Artificial Cilia for In Situ Monitoring of Airway Physiological Properties"

Continuously monitoring human airway conditions is crucial for timely interventions, especially when airway stents are implanted to alleviate central airway obstruction in lung cancer and other diseases. Here, we report wireless sensing mechanisms in sensory artificial cilia for detecting mucus conditions, including viscosity and layer thickness, which are crucial biomarkers for disease severity. We integrate Bluetooth Low Energy communication and onboard power, along with a wearable magnetic actuation system for sensor activation. The proposed sensing mechanisms and devices pave the way for real-time monitoring of mucus conditions, facilitating early disease detection and providing stent patency alerts, thereby allowing timely interventions and personalized care.

ANNA KITTEL
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Hybrid Shear-Thinning Hydrogels as an Injectable Delivery Platform for Regeneration of Diabetic Skin Wounds"

Diabetes makes patients susceptible to formation of chronic, nonhealing skin wounds. While stem cells are promising in promoting wound repair, chronic wounds are characterized by uncontrolled inflammation and overproduction of reactive oxygen species (ROS), limiting viability and benefits of cell therapies. We tested a nanoparticle (NP) and hyaluronic acid (HA) composite shear-thinning hydrogel for delivery and protection of stem cells or stem cell-derived extracellular vesicles (EVs) in diabetic skin wounds. The NP component is ROS scavenging/degradable, while HA was chosen due to its bioactive, pro-regenerative function. We found that hydrogel delivered cells and EVs promoted greater wound healing than control treatments.

EMMA ENDRES
Graduate Student, Chemistry
PI: Janet Macdonald

"Influencing cation coordination through the addition of phosphine ligands in colloidal nickel sulfides nanocrystal syntheses"

Multiple methods to achieve phase control of colloidal nanoparticles have been explored, such as reagent reactivities, reaction parameters, and ion exchange. These routes each have their own limitations. Here we combine ideas from these approaches, focusing on structure while also influencing precursor reactivity. Concepts from coordination chemistry are intentionally employed to manipulate the metal in solution, thus affecting the interstitial holes the metal fills in the solid. Phosphine ligands of varying bite angle, steric bulk, and electron donation ability are added to influence the nickel and the resulting nickel sulfide phase. Through this, we found that the steric property of the phosphine had the greatest effect. By varying the phosphine added, millerite (NiS), heazlewoodite (Ni3S2), and godlevskite (Ni9S8) were selectively targeted.

MAXWELL UGWU
Graduate Student, Interdisciplinary Materials Science
PI: Justus Ndukaife

"Rapid Immobilization and characterization of extracellular vesicles with the geometry induced electrohydrodynamic nanotweezer"

Extracellular vesicles (EVs) are crucial for cell communication, but their significant heterogeneity makes isolating specific types from their complex mixtures challenging. In this study, we are investigating the sorting capabilities of geometry-induced electrohydrodynamic nanotweezers (GET) functionalized with monoclonal antibodies that selectively bind to a vesicular CD9 surface protein. This method enables rapid and precise immobilization of EVs expressing the target protein, providing a powerful tool for targeted vesicle sorting. We employ Raman spectroscopy, atomic force microscopy, and electron microscopy to analyze the cargo composition and surface morphology of immobilized vesicles. This integrated GET-antibody system shows great promise for isolating cancer-derived vesicles for early diagnostics.

RYAN OCCHIONERO
Graduate Student, Mechanical Engineering
PI: Jason Valentine

"Improving Fabrication Techniques for Silicon Based Imaging Metaoptics"

This poster showcases my work on a edge detection metasurface and a varifocal Moiré metasurface pair, highlighting fabrication improvements that enhance optical performance.

Edge detection is vital in computer vision algorithms employed in object classification and tracking. However, advanced performance algorithms require high computational power. An analog edge detector metasurface which physically yields low-level edge features could offload digital processing.

Varifocal imaging typically require bulky, axially actuated lenses to adjust focal length. Moiré lenses achieve varifocal capabilities through simpler, rotational actuation of two ultra-thin metalenses.

HONGLU LIN
Graduate Student, Mechanical Engineering
PI: Xiaoguang Dong

"Wirelessly Actuated Microfluidic Pump and Valve for Controlled Liquid Delivery in Dental Implants"

Enabling minimally invasive and precise control of liquid release in dental implants is crucial for therapeutic functions such as delivering antibiotics to prevent biofilm formation, infusing stem cells to promote osseointegration, and administering other biomedicines. However, achieving controllable liquid cargo release in dental implants remains challenging due to the lack of wireless and miniaturized fluidic control mechanisms. Here wireless miniature pumps and valves that allow remote activation of liquid cargo delivery in dental implants, actuated and controlled by external magnetic fields (<65 mT), are reported. A magnet-screw mechanism in a fluidic channel to function as a piston pump, alongside a flexible magnetic valve designed to open and close the fluidic channel, is proposed. The mechanisms are showcased by storing and releasing of liquid up to 52 µL in a dental implant. The liquid cargos are delivered directly to the implant–bone interface, a region traditionally difficult to access. On-demand liquid delivery is further showed by a metal implant inside both dental phantoms and porcine jawbones. The mechanisms are promising for controllable liquid release after implant placement with minimal invasion, paving the way for implantable devices that enable long-term and targeted delivery of therapeutic agents in various bioengineering applications.

SARAH HALL
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Ultrahigh Paclitaxel-loaded Nanoparticles for the Treatment of Triple Negative Breast Cancer"

TNBC accounts for over 15-20% of all breast cancers. Motivated by the need to improve treatments, we designed polymeric nanoparticles (NPs) to achieve ‘ultrahigh’ loading (LC ≥ 35%) of the chemotherapy paclitaxel (PTX) to increase PTX maximum tolerated dose (MTD) and consequently anti-tumor efficacy. The NP system is comprised of ABA triblock copolymers that possess a tunable, ROS-triggered release mechanism. Herein, we have investigated the therapeutic efficacy in an orthotopic TNBC model of two NP compositions that have varied ROS sensitivity, yielding “slow” and “fast” drug release formulations. The “slow” group showed complete tumor elimination in 3 out of 8 mice, and both formulations demonstrated therapeutic efficacy superior to the clinical standard, Taxol.

LAUREN LINK
Undergraduate Student, Biomedical Engineering
PI: Todd Giorgio

"Optimizing a Nanoparticle Drug Delivery System to Treat Preterm Labor"

Preterm labor is the leading cause of infant mortality and morbidity worldwide, yet no pharmacological treatments currently exist to combat it. Although potentially effective therapies exist to suppress undesirable uterine contractions, these drugs often transport across the placental barrier, leading to adverse consequences on the developing fetus. Formulation strategies to limit fetal exposure may enable the safe and effective use of currently approved drugs for the prevention of preterm birth. We hypothesize that optimally sized PLGA particles formulated with an anti-tocolytic will sharply limit placental transport and suppress uterine contractions. Therefore, we synthesized cargo-loaded PLGA particles with an oil-in-water emulsion fabrication technique, evaluating drug release and biodistribution properties to determine system efficacy.

NATHANIEL KAROM
Graduate Student, Physics & Astronomy
PI: Sharon Weiss

"Multi-Scale Simulation Framework for Predicting Radiation Response in Nanophotonic-Electronic Systems"

Development of a multi-scale simulation approach for radiation effects on nanophotonic-electronic devices is presented. This includes coupling of radiation transport models to nanophotonic and electronic device simulations to better understand their response to radiation exposures.

HAYDEN PAGENDARM
Graduate Student, Biomedical Engineering
PI: John Wilson

"Albumin-binding nanobody-antigen fusions enhance antigen presentation and improve vaccine responses through pharmacokinetic modulation"

Peptide vaccines hold the potential to treat many diseases. These therapies utilize the exact antigen epitopes (~2 kDa) that are presented by major histocompatibility complexes (MHCs). Unfortunately, the efficacy of peptide-based vaccines has been limited due to inefficient trafficking to the draining lymph node (dLN), rapid renal clearance, susceptibility to proteolysis, and presentation in an inappropriate context without the spatiotemporal co-delivery of an adjuvant. To address this, we have developed a platform for peptide antigen delivery using a nanobody (Nb) targeting mouse serum albumin (MSA) (nAlb). Additionally, we demonstrated that nAlb-antigen vaccine responses can be augmented via the inclusion of a targeting nanobody domain to enhance delivery to effector cells.

MEGAN KEECH
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Therapeutic siRNA conjugates for osteoarthritis"

Osteoarthritis (OA) is a degenerative joint disease associated with aging or injury. Current treatments focus on symptom management but lack disease modifying osteoarthritis drugs. We are innovating siRNA conjugates leveraging our recently established a novel, carrier-free diacyl lipid end-modified siRNA (siRNA-L2) platform that, delivered intravenously achieves potent and long-lived target gene silencing in OA joints. Building on our successful work targeting Mmp13, we are investigating new targets of interest in order to further develop a more potent disease modifying OA drug capable of modulating disease progression and treating symptoms.

ADITHA SENARATH
Graduate Student, Interdisciplinary Materials Science
PI: Josh Caldwell & Ronald Schrimpf

"Near-Field Investigation of Hybrid Surface-Phonon-Plasmon Polariton in Doped Gallium Nitride for Enhanced Infrared Characterization"

Wide bandgap (WBG) semiconductors, such as gallium nitride (GaN), are crucial for next-generation high-power and high-frequency devices due to their unique properties. This study examines GaN’s infrared (IR) response, focusing on hybridized surface phonon-plasmon polaritons (SPPPs) arising from interactions between polar optical phonons and free carriers. The frequency-wavevector dispersion of these modes was obtained using near-field IR reflection measurements from a free electron laser (FEL) coupled scattering-type scanning near-field optical microscopy (s-SNOM). Findings show that SPPP dispersion is highly sensitive to doping densities, illustrating that the polariton-based approach could serve as a powerful tool for probing carrier density, strain, and defects in WBG materials.

HANNAH RICHARDS
Graduate Student, Chemistry
PI: David Cliffel

"Constructing Self-Assembled Layers on Magnetic Beads for Electrochemical Immunoassay Development"

Reproductive research does not advance at the rapid rate of other organ systems, leading to a significant demand for new analytical techniques that quantify preterm birth (PTB) inflammatory cytokines, such as interleukin-1β (IL-1β), elevated during preterm birth (PTB) cases. In this work, we have developed an immunoassay based upon 2.8 µm magnetic beads, an alternative to traditional enzyme-linked immunosorbent assays (ELISAs), for the rapid electrochemical detection of IL-1β. We present comprehensive characterization of the immunoassay while showcasing the ability to reproducibly detect IL-1β levels up to 600 pg/mL in biological media. Future work includes optimizing the electrochemical performance of the MBESA to further elucidate PTB mechanisms.

MADISEN DOMAYER
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Hyaluronic acid with Bioadhesive properties for the delivery of high drug-loading nanoparticles for the treatment of Osteoarthritis"

Osteoarthritis is a chronic condition that leads to the degradation of cartilage, causing joint pain and disability. Current treatment options include corticosteroid and hyaluronic acid (HA) injections, but these treatments only provide temporary relief and do not slow the progression of disease. As a result, patients are often ultimately relegated to total joint replacement. HA consistently reduces joint pain associated with OA, but the half-life of HA is relatively short. Here, we are modifying HA to create bioadhesive, shear-thinning, hydrogels that are a composite of HA and nanoparticles. This design seeks to afford prolonged patient relief and also an opportunity for combining the benefits of HA with sustained local drug release from the nanoparticle component of the hydrogel. Furthermore, the NPs will be formed from polysulfides, an ROS responsive class of polymers that have inherent antioxidant, therapeutic function in the context of OA.

CHRIS BOYD
Graduate Student, Mechanical Engineering
PI: Jason Valentine

"Metasurface-Enhanced Motion Estimation in Event-Based Vision"

Event-based (EB) cameras are neuromorphic vision tools that, unlike traditional cameras, capture continuous streams of motion-activated events through asynchronous pixel response. This is particularly advantageous for optical flow, a computer vision technique used to calculate and visualize object motion relative to the camera. However, EB optical flow calculations are often hindered by a “bleeding edge” effect— trailing artifacts that distort motion accuracy. To address this, we integrate metasurfaces—ultrathin optics with periodic nanostructures designed to manipulate the phase, amplitude, and polarity of light—as edge filters using a Laplacian point spread function. Simulations demonstrate that this approach reduces event density by over 50%, minimizes the bleeding edge, and enhances computational accuracy and processing speed, advancing EB optical flow performance for dynamic vision applications.

HARRISON WALKER
Graduate Student, Interdisciplinary Materials Science 
PI: Sokrates Pantelides

"Polar-Topology-Mediated Phonons in Ferroelectric Superlattices"

Ferroelectric PbTiO3/SrTiO3 superlattices host diverse polar domain configurations including flux-closures, vortices, skyrmions, and merons at the nanoscale. While sub-THz "vortexon" phonon modes have been observed in the vortex phase, their broader influence on phonon behavior remains unexplored. Here, we combine monochromated scanning transmission electron microscopy and electron energy-loss spectroscopy (STEM-EELS) with machine-learning molecular dynamics (MLMD) to investigate the full vibrational spectrum of these topological structures. Analysis reveals significant modifications to both acoustic and optical phonons, including spatially dependent phonon softening and the emergence of new modes specific to vortex topological structures. Notably, we discover a distinct dichroic phonon response that correlates directly with vortex handedness, demonstrating an intricate coupling between structural topology and vibrational dynamics.

ADAM ABDULRAHMAN
Graduate Student, Biomedical Engineering
PI: Ethan Lippmann

"Targeted siRNA Delivery to Border-Associated Macrophages in Neurodegeneration"

Chronic inflammation plays a central role in neurodegenerative diseases, with border-associated macrophages (BAMs) emerging as key effectors in neuroinflammatory processes. BAMs, located at the brain’s perivascular and meningeal borders, contribute to both protective and pathological mechanisms, making them promising therapeutic targets. This work focuses on developing lipid-siRNA conjugates designed for selective BAM delivery, with an emphasis on dose optimization for effective targeting in the perivascular spaces. Additionally, trimannose conjugation is employed to exploit the mannose receptor (CD206) on BAMs, enhancing specificity and uptake. Early results demonstrate successful siRNA delivery with optimized dosing, paving the way for future in vivo studies to further investigate BAM-targeted therapies in neurodegenerative models.

KIYOUNG KIM
Graduate Student, Mechanical Engineering
PI: Xiaoguang Dong

"Mucosa-Interfacing Capsule for In-Situ Sensing the Elasticity of Biological Tissues"

Monitoring the elasticity of soft biological tissues in the gastrointestinal (GI) tract with minimal invasion holds promise for early diagnosis of intestinal fibrosis, colorectal cancer, and other diseases featuring abnormal elasticity. However, existing methods of sensing tissue elasticity have drawbacks such as insufficient resolution for elastography, and discomfort or the requirement of risky anesthesia for flexible endoscopes or implantable devices. Here we present a wirelessly actuated palpation mechanism integrated into a swallowable capsule robot, offering in situ tissue elasticity measurement with minimal invasiveness. Our approach employs a magnetic soft cantilever beam actuated by external magnetic fields to gently press against soft tissue. Mechanical stress and strain are monitored by an onboard magnetic sensor and a strain gauge, allowing for accurate assessment of tissue elasticity. Additionally, wireless modules utilizing Bluetooth Low Energy and powered by a battery facilitate real-time communication. The robot operates under external magnetic field control, which can move freely over soft tissues during examinations and palpate suspicious areas. We validate and assess the elasticity sensing mechanism on both phantom structures and ex vivo porcine colon tissues. Our capsule robot holds significant promise for assessing tissue physiological conditions and facilitating early disease diagnosis in hard-to-reach areas of the body.

ZACH LAMANTIA
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Engineering the CRISPR-Cas9 Ribonucleoprotein Complex for Carrier-Free Gene Editing"

Despite the rapid development of CRISPR-Cas9 delivery technology for gene editing, translating these therapies into the clinic for in vivo editing has proven to be a challenge. Our work focuses on increasing the stability and pharmacokinetics of the CRISPR-Cas9 RNP complex to allow its systemic delivery for in vivo editing of muscle. This work aims to utilize RNA chemical modifications to improve the in vivo stability and pharmacokinetics of CRISPR-Cas9 RNPs. Plasmid cleavage assays and in vitro gene editing studies in primary Ai9 reporter mouse cells are used to assess the activity of the modified RNPs, while serum stability challenges are used to investigate stability benefits. We show that these modifications provide significantly increased stability against nuclease degradation. Therefore, we have found that the incorporation of chemical modifications to the dgRNA system retains editing activity and that these modifications improve the stability of the complex. Future work will continue to explore different chemical modification patterns and the integration of these modified RNPs in vivo to determine their effects on pharmacokinetics and gene editing activity.

Poster has been withdrawn

ANDREY SHULTS
Graduate Student, Chemistry
PI: Janet Macdonald

"Decomposition of Selenourea in Various Solvents: Red vs Grey Selenium in the Synthesis of Iron Selenide Nanoparticles"

Selenourea is a practical selenium precursor choice for low temperature colloidal syntheses. This study examines how ubiquitous ligands in nanoparticle synthesis influence the decomposition of selenourea, specifically for the synthesis of iron selenides. Through the use of X-ray diffraction, nuclear magnetic resonance, and gas phase Fourier transform infrared spectroscopy, we show that in the presence of oleylamine, red selenium forms and can be used to synthesize Fe7Se8 nanoparticles; while in the presence of oleic acid, grey selenium forms and gives rise to FeSe2 nanoparticles. For the first time, allotropes have been identified as phase-determining intermediates in metal chalcogenide synthesis.

SEBASTIAN FLORES
Graduate Student, Chemistry
PI: Sandra Rosenthal

"Shelling of Giant Tetrahedral InP and InGaP Quantum Dots"

Quantum dots (QDs) are semiconductor nanocrystals with size-tunable absorption and emission properties due to quantum confinement. In an effort to take full advantage of QDs unique properties, cadmium-free, non-toxic materials based on indium phosphide (InP) have been developed. Building off these methods, Ga3+-doping of InP QDs has gained traction due to its potential to expand the emission range of InP by blue-shifting the fluorescence while maintaining a photostable size. The proposed study would involve the synthesis and characterization of InGaP/ZnSe QDs, as well as an ultrafast fluorescence study to investigate Ga3+ role in the electron dynamics of alloyed InGaP/ZnSe QDs.

BRADLY BAER
Graduate Student, Interdisciplinary Materials Science
PI: Greg Walker

"Molecular dynamics simulations of thermal transport in metals using a two-temperature model"

Molecular dynamics (MD) simulations are an important tool in modeling thermal transport properties. However, their basis in classical mechanics gives an incomplete picture of thermal transport in metals. Classical mechanics accounts for thermal transport by phonons but ignores the thermal transport contribution of the electrons. Depending on the metal, this can leave over 95% of the total thermal conductivity unaccounted for. We use a two-temperature model to integrate electron transport into MD simulations to produce accurate thermal transport properties in metallic systems.

LARRY STOKES
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Development of a Carrier-Free CRISPR/Cas9 Technology for Systemic Gene Editing"

More than 4000 monogenic mutations are responsible for at least 80% of all rare diseases. The monogenic nature of these mutations makes many rare diseases potential candidates for CRISPR/Cas9 gene therapies; however, many delivery barriers must be overcome to achieve therapeutic levels of gene correction. To date, most research has focused on designing and optimizing viral vectors or lipid nanoparticles to deliver Cas9 in various cargo forms, but these delivery systems have associated drawbacks that make them ineffective for broader, systemic diseases such as Duchenne’s Muscular Dystrophy (DMD). This creates a need for a Cas9 system that can act as a carrier-free gene editing therapeutic. To this point, researchers have shown that albumin accumulates into injured muscle fibers in mdx mice. By leveraging albumin hitchhiking, a carrier-free Cas9 therapy could be developed to target systemic diseases such as DMD.

BOYANG XIAO
Graduate Student, Mechanical Engineering
PI: Xiaoguang Dong

"Wireless Microfluidics Enabled Miniature Soft Robots for Targeted Fluid Delivery and Sampling"

The integration of wireless microfluidics in untethered soft robots has the potential to revolutionize biofluid sampling for diagnostics and enable on-demand delivery of bioagents to hard-to-reach areas. However, this integration remains challenging due to the lack of wirelessly controlled microfluidic modules that can be seamlessly coordinated with the robot’s locomotion. Here we propose a fundamental wireless pumping and valving mechanism that enables millimeter-scale soft climbing robots to perform fluidic functions such as liquid ejection and collection, entirely under remote magnetic control. By integrating wireless pumps, valves, and microfluidic channels into miniature soft robots, our proposed robots offer unique capabilities for targeted drug delivery and biofluid sampling, paving the way towards minimally invasive soft miniature robots.

KELLEN ARNOLD
Graduate Student, Interdisciplinary Materials Science
PI: Sharon Weiss

"Photonic Integrated Circuits for Next-Generation Space Missions: Navigating Harsh, Radiation-rich Environments"

The requirements on performance and efficiency of integrated circuits for space mission instrumentation necessitates the inclusion of on-chip photonics, which offers light-speed data communications rates with low power consumption and footprint. However, the harsh radiation environment in space poses critical challenges to reliability of all devices and systems; radiation exposure generates unwanted defects and trapped charge that can affects signal integrity and device lifespan. Understanding and mitigating these radiation effects is essential for developing resilient photonic systems for long-term space missions. This research examines the mechanisms of radiation-induced damage in Mach Zehnder modulators and explores strategies for enhancing radiation hardness, aiming to support robust photonic systems for next-generation space applications.

BRAYDEN TERRY
Graduate Student, Interdisciplinary Materials Science
PI: Alvin Strauss

"Friction Stir Welding of Thin Sheet NiTi Shape Memory Alloy and Ti-6Al-4V"

Friction stir welding of butted 1 mm thick sheets of NiTi and Ti-6Al-4V was tested under a matrix of welding parameters. Six of eight tested parameter conditions joined but each showed degraded mechanical properties. Higher traverse speed conditions joined more successfully into testable samples. Upper and lower quartiles for tensile strength varied between 140 to 60 MPa with the lower rotation speed showing higher median values. Weld degradation is attributed to the formation of an up to 10 µm wide Ti2Ni intermetallic compound layer at the weld interface. Higher rotation speeds showed a thicker intermetallic layer. The Ti2Ni layer showed equiaxed grains on the order of 2-3µm in diameter. It is theorized that this layer grew from pre-existing Ti-6Al-4V via nickel diffusion from the NiTi due to in-process heating. XPM nanoindentation shows that the Ti2Ni layer has a greater microhardness and reduced elastic modulus (12.42 GPa and 150.06 GPa) than the stir zone of the NiTi (5.10 GPa and 97.65 GPa) and Ti-6Al-4V (5.93 GPa and 137.2 GPa). Crack propagation along this brittle, high stiffness intermetallic layer is proposed as the cause of failure in the welded samples.

CHARLES FRECH
Undergraduate Student, Biomedical Engineering
PI: Leon Bellan

"3D-Printing of Branching Networks in Hydrogels Suitable for Vascular Anastomosis"

We modified a commercial mSLA resin 3D printer to enable stereolithographic printing of hydrogel-based microfluidic devices. The hydrogels were composed of 700 MW polyethylene glycol diacrylate (PEGDA 700), the UV blocker tartrazine, and the photo-initiator lithium phenyl (2,4,6-Trimethylbenzoyl) phosphinate (LAP). Printer settings, including exposure time and layer height, were tuned to optimize feature size of different formulations. Furthermore, hydrogel formulations were adjusted to achieve desirable mechanical properties. The inlet and outlet channels within the hydrogel were ultimately anastomosed to a vessel within a chicken thigh to test the construct’s effectiveness as implantable pre-vascularized engineered tissue.

IKJUN HONG
Graduate Student, Electrical and Computer Engineering
PI: Justus Ndukaife

"Narrow-band, highly directional thermal emitter driven by a non-local magnetic anapole metasurface"

The demand for coherent infrared sources is increasing for applications like high-resolution gas sensing, medical diagnostics, and night vision. We propose thermal emitters composed of an Au metal layer, an Al₂O₃ spacer, and an Au reflector. These emitters leverage magnetic anapole mode coupled with localized lattice surface plasmons to produce highly angle-dispersive, coherent radiation. By incorporating large holes in Au pillars, we achieve a single-peak emission at 4.37 µm with a high-quality factor of ~120 and a narrow divergence angle of ±1.1°. This structure also offers temperature-independent performance, promising applications in photonics, sensing, and spectroscopy.

SHANNON MARTELLO
Graduate Student, Chemical and Biomolecular Engineering
PI: Marjan Rafat

"Neutrophil-Vasculature Interactions Promote Pro-Recurrent Niche Formation Post-Radiotherapy"

Triple negative breast cancer (TNBC) patients are at significant risk for locoregional recurrence, yet the mechanisms that underly prognostic factors such as a high post-radiotherapy (RT) neutrophil-to-lymphocyte ratio remain unclear. Our lab previously demonstrated that RT-damaged cells and mammary adipose tissue foster a pro-tumor microenvironment that promotes recurrence. Mammary adipose tissue is highly vascularized, and we therefore hypothesize that following RT, damaged vasculature recruits and primes neutrophils towards a pro-tumor phenotype creates a niche favorable for CTC outgrowth. We tested this hypothesis by characterizing neutrophil and vascular changes using an in vivo TNBC recurrence model and probing neutrophil-endothelial cell interactions in vitro using traditional cell culture methods. These observations were then used to develop an in vitro organ-on-a-chip model of the mammary gland vasculature that incorporates fluid flow and shear stress to probe mechanisms of our in vivo observations in a more biologically relevant system. Ultimately, using this organ-chip model to probe molecular and cellular interactions will improve our understanding of TNBC recurrence mechanisms and reduce the number of animals required for translational experiments.

PATRICIA POLEY
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Sustained Release of siRNA from Antioxidant Polymer Microparticles for the Treatment of Osteoarthritis"

When reactive oxygen species (ROS) levels exceed the body’s natural antioxidant abilities, cells experience oxidative stress, which can cause inflammation and cell death. This contributes to the pathogenesis of degenerative diseases, such as osteoarthritis (OA). Oxidative stress stimulates expression of enzymes that destroy extracellular matrix, with matrix metalloproteinase 13 (MMP13) being a primary culprit in cartilage breakdown in OA. We hypothesized that sustained siRNA (siMMP13) delivery using an antioxidant polymer-based microparticle system would synergize to inhibit degradation of cartilage, reducing joint damage caused by post traumatic osteoarthritis (PTOA). The antioxidant polymer, poly (propylene sulfide-co-ethylene sulfide) (PPSES), was formulated into microparticles loaded with siMMP13, and injected intraarticularly into mice to reduce ROS and inhibit MMP13. After four weeks of repeated cyclic loading, tissues of interest were harvested for qPCR. PPSES-siMMP13 MPs achieved ~86% knockdown compared to a control sequence, indicating sustained silencing with PPSES-siMMP13 delivery. As a complement to this promising result, ongoing work is investigating the ROS scavenging of PPSES and related polymer chemistries in the context of PTOA.

GRACE ADAMS
Graduate Student, Biomedical Engineering
PI: Daniel Gonzales

"Transparent polymer-based electrodes for combined electrophysiology and two-photon imaging"

Electrophysiology-based neural interfaces can measure neural activity on the millisecond scale, on par with the timing of neuronal firing. However, traditional opaque silicon electrode arrays are incompatible with two-photon imaging, which can provide cell-specific spatial and structural information. We are developing transparent, polymer-based arrays to allow for stable electrophysiological recordings paired with cell-specific imaging of neurons surrounding the implant. Furthermore, we are implementing indium-tin oxide (ITO) as a transparent alternative to conventional metal conductive layers. By balancing electrode geometries, ITO electrodes can be scaled down to near the cellular scale with a sufficiently low electrochemical impedance while achieving sufficient transparency.

BORISLAV IVANOV
Laboratory Assistant, Chemical and Biomolecular Engineering
PIs: Kane Jennings / Borislav Ivanov

"Development of Piezoresistive MEMS Approach for Monitoring of Pathogens in Human Breath and Aerosols"

For prevention of outbreak the active pathogens must be detected instead of their fragments as PCR do with 6 days delays from infection beginning. We are developing piezoresistive MEMS cantilevers sensors, working in differential mode to reduce signal drift and background noise, being usual issues for standard optical detection cantilever sensors. In addition to MEMS sensors, the electronics device for measurement of resonance frequency of MEMS cantilevers and corresponding software was developed. The MEMS system was tested by Self Assembled Monolayers of thiolate compounds and protein immobilization.

GUODONG ZHU
Graduate Student, Electrical and Computer Engineering
PI: Justus Ndukaife

"Engineering thermal emission with superior emissivity and quality factor using bound states in the continuum and electromagnetically-induced absorption"

This research addresses the challenge of achieving high emissivity and quality factors in thermal emitters with metal-insulator-metal (MIM) structures. By leveraging the electromagnetic induced absorption (EIA) between two bound states in the continuum (BIC) resonance modes and a relatively low quality factor resonance mode in an asymmetric metallic ring structure, we demonstrate a metasurface design with a near-unit emissivity and a quality factor as high as 320 theoretically, without strict to critical coupling. The significant improvement can be attributed to the strong light-matter interaction and constructive interference enhancing absorption through EIA achieved with BICs. Experimental results validate the theoretical predictions, showing the peak emissivity of 0.82 and a record measured Q factor of 210 for metal-based thermal emitters, with robust temperature stability and directional emission. This study offers a promising approach to developing efficient narrow-band thermal emitters for applications such as infrared sensing, communication, and environmental monitoring.

MARK MC VEIGH
Graduate Student, Interdisciplinary Materials Science
PI: Leon Bellan

"Automated Fluorescent Labeling of IgG Using the RAPID Platform"

Positron Emission Tomography (PET) is a diagnostic staple of oncology that relies on radioactively labelled biomolecules (“radiotracers") to target malignancies with high precision and specificity. The biomolecules range from generic small molecules to highly specific biologics, but the current radiotracer production pipeline cannot affordably produce more specific but less frequently used radiotracers. RAPID is a microfluidic radiotracer synthesis platform being developed to automatically and affordably synthesize single doses of any radiotracer. The RAPID-M microfluidic chip (which performs radiometal labeling) has been redesigned to work with large biomolecules, and an accompanying automation unit has been developed. To test operation of the system without radioactivity, we demonstrate automated labeling and purification of human IgG with AlexaFluor 488.

JORDAN HILL
Graduate Student, Biomedical Engineering
PI: Craig Duvall

"Modifying siRNA Delivery Using Blue Light PET-RAFT Polymer Conjugates"

We evaluated the pharmacokinetic characteristics of a library of siRNA-polymer conjugates and
elucidated a minimum polymer size of 40 kDa to reduce renal clearance as well as increase the
bioavailability of the conjugates. We optimized reaction conditions for the polymerization of pDMA in a 384-well plate, created a siRNA macro-RAFT agent, and established a library of pDMA conjugates from 20 to 100 kDa. Conjugates over 40 kDa all showed increased half-life, decreased accumulation in the kidney, and increased accumulation in the liver. This size-dependent decrease in clearance rates translated into significant improvements in overall tissue distribution.

COURTNEY RAGLE
Graduate Student, Interdisciplinary Materials Science
PIs: Lauren Buchanan & Josh Caldwell

"Vibrational Strong Coupling for Control in Chemical Reactions"

Vibrational polaritons afford us a revolutionary way to approach energy exchange mechanisms. Between molecular vibrational polaritons and phonon (lattice vibrations) polaritons, the possibilities are endless. Coupling strengths for this mechanism can be quantified using readily available microscopy (SNOM) and two-dimensional infrared spectroscopy (2DIR). Utilizing these quantification methods, we aim to design a system in which coupling strength is maximized by minimizing cavity mode volumes via shrinking cavity widths and translating into Fabry Perot like hyperbolic polariton cavities.

DANIEL WOODS
Graduate Student, Biomedical Engineering
PI: Daniel Gonzales

"Fabrication of flexible, transparent electrodes for acute recordings in non-human primates"

State-of-the-art, high density in vivo electrophysiology probes are often silicon-based, but their rigidity poses challenges for recording stability in the brain's soft tissue. Flexible polymer-based probes offer improved mechanical compliance and biocompatibility, allowing for more robust recordings. Additionally, their transparent design enhances optogenetic applications, which uses light to selectively stimulate neurons, a rapidly advancing technique in neuroscience. Using VINSE cleanroom facilities, these probes were manufactured with impedances measuring ~1 MOhm. This work presents the fabrication of such electrodes for acute recordings in non-human primates, as well as novel methods of implanting the devices, demonstrating their potential for high-yield and stable neural data collection.

ZACHARY MARTIN
Graduate Student, Electrical and Computer Engineering
PI: Sharon Weiss

"Simulation and Design of Superimposed Rugate Filters"

Colorimetric sensing for point of care diagnostics offers a promising level of sensitivity, but current designs require the use of multichromatic lasers. While inexpensive compared to most scientific equipment, these lasers still limit the availability of diagnostic tools to people that do not have access to laser instrumentation. To overcome this challenge, a multiple stop band rugate filter can be used to replicate the function of a multichromatic laser. This work explores the design of a rugate filter to maximize the reflectivity of red, green, and blue wavelengths when illuminated from a smartphone’s white light.

MAILEE SRILOUANGKHOL
High School Student, John Overton High School
PI: Leon Bellan

"Thermoresponsive Hydrogels for Cooling-Triggered Drug Release"

PNIPAM was used in P-C, a device developed prior and acts as a local carrier for Bupivacaine in a post operative site, with a cooling-trigger. Cloud point and cooling-triggered temperatures were tested further. An apparatus was made to measure transmittance and temperature for PNIPAM solutions. 5 temperatures were chosen ranging from 23°C to 31.5°C with P-C for 60 minutes using fluorescein. Cloud points of blank PNIPAM were on average 28.5°C, while Bupivacaine-laden PNIPAM differed. The best ‘on’ temperature was 23°C, with 2.35% fluorescein release per hour, and best ‘off’ temperature is 30°C, with 0.01% fluorescein release per hour, which aligns with PNIPAM’s LCST activity. Overall, P-C was better studied and further prepared to test in-vivo.

ABRAM SHEA
High School Student, John Overton High School
PI: Kane Jennings

"Block-like Membranes by scROMP for Polar Solvent Dehydration"

Current methods of ethanol dehydration, primarily distillation, use large quantities of energy. A new method of separation which uses much less energy involves membranes. The main industrial membrane for ethanol dehydration is PVA. PVA synthesis takes a large amount of time. Due to its lack of olefin groups, PVA cannot be synthesized using the quicker scROMP method. Therefore, this study sought to create a membrane that mimicked PVA’s functionality while still allowing for faster synthesis using scROMP. This was accomplished using block-like copolymers modified in various polar solvents. pNBDAC-b-pDPCD (tris) performed the best, with a selectively of 10. Despite showing promise, pNBDAC-b-pDCPD modified membranes are not to the level of effectiveness to be able to replace PVA for ethanol dehydration.

LIAM CHAPMAN
High School Student, Hillsboro High School
PI: De-en Jiang

"Investigation of Thermodynamics Between Carbanion and Carbon Dioxide Reactions for Carbon Capture"

Cleaning the increasing concentration of CO2, which has created environmental problems, through carbon capture reactions is increasingly needed. However, carbon capturing possesses a high energy cost. My investigation was into four carbanions to determine which was the most efficient carbon capture. 3D construction and computational calculations, followed with a comparison of their simulated reaction energy gave the result. Carbanion C4H4NO3S consistently had the lowest enthalpy value. C4H4NO3S is the most cost-efficient of the investigated molecules for carbon capture. This information is vital in developing carbon capture technology, so it’s favorable for use to eliminate excessive CO2 emissions large scale.

JOSEPH LONG
High School Student, Hillsboro High School
PI: Leon Bellan

"Investigating the Bond Strength of RAPID Devices"

RAPID (Radiopharmaceuticals as Precision Imaging Diagnostics) are microfluidic devices that synthesize radiotracers affordably in on demand doses. In this study the bond strength of RAPID devices was tested under different fabrication procedures, operating conditions, and ethanol exposures to maximize its efficiency. This was done through burst tests using the psi at which the device bond failed as a gauge of bond strength. The results of the study found that the fabrication procedure is within a robust window, clamping the fluidic interface minimally increases fluid pressure capacity, and ethanol exposure weakens the bond strength of RAPID devices.a

LILLIE CATE ALLEN
High School Student, Hillsboro High School
PI: Piran Kidambi

"Optimizing the Porosity of Different PVDF Castings"

As energy usage increases, its production must become more efficient. Some of the best energy sources are fuel cells, which use chemical reactions to produce energy. Inside each cell, a proton exchange membrane is used to filter atoms. They are made of a carbon structure, called graphene, that must be paired with a polymer to provide structure. Adding the polymer polyvinylidene difluoride, or PVDF, provides high thermal resistance and uniform pores across the membrane surface. This project seeks to study PVDF castings while also looking for consistent pores throughout the membranes, in hopes of creating more efficient fuel cells.

CARSON SNOW
1st year Graduate Student, Interdisciplinary Materials Science
PI: Josh Caldwell

"Dispersion Control of Light in Highly Anisotropic 2-D Materials"

Controlling the dispersion of light in highly anisotropic two-dimensional (2D) materials offers exciting opportunities for nanoscale optical manipulation. In this work, we explore twisted heterostructures of isotopically enriched molybdenum trioxide (MoO₃), a material renowned for its strong in-plane anisotropy, as a platform for managing light propagation. By precisely adjusting the twist angle between the layers, we demonstrate control over the dispersion of unidirectional ray polaritons (URPs), which are notable for their large momenta and tunable phase. These polaritons exhibit unique directional behavior, which can be modulated through variations in both the twist angle and illumination frequency. Our findings provide a framework for manipulating light-matter interactions in 2D anisotropic materials, with potential applications in fields such as nanoimaging, sensing, and thermal management. This research advances our understanding of light dispersion in van der Waals materials, contributing to the development of novel optical technologies.

BHARAT BHARAT
1st year Graduate Student, Interdisciplinary Materials Science
PI: Janet Macdonald

"Hybrid Plasmonic colloidal Nanostructures: A Pathway to On-Chip Optical Materials for Ultrafast Spectroscopy and Quantum Computing"

Nonlinear optical materials are pivotal for quantum computing, ultrafast communications, and optical switching, yet they face limitations in scalability, tunability, and the need for phase matching. Our innovative approach leverages plasmon-plasmon harmonic coupling between colloidal hybrid nanoparticles functionalized with DNA to assemble them, significantly enhancing non-linear optical processes such as harmonic generation efficiency. This method eliminates the need for phase matching and is paintable, opening doors to advanced spectroscopies and next-generation quantum devices. In the long term, this research could contribute to the development of on-chip optical materials for ultrafast spectroscopy and photon pair generation, revolutionizing quantum computing and telecommunications.

EMANUELA RIGLIONI
1st year Graduate Student, Interdisciplinary Materials Science 
PI: Mona Ebrish

"Optimization of etch, release, and transfer of GaN HEMTs devices"

GaN-based high electron mobility transistors (HEMTs) devices offer significant potential for high-power and high-frequency applications, yet the heterogeneous integration of these devices with other material systems remains a key challenge. This study focuses on optimizing the etching, release, and transfer processes for GaN devices on commercially available Qromis QST wafers. A nickel hard mask was developed to enhance etching precision, and tailored tether structures were designed to facilitate device release in a xenon difluoride (XeF₂) environment. Furthermore, adhesion layers as thin as 67 nm were achieved and successfully employed in the micro-transfer printing process, yielding a high success rate for device transfers.

KE-SEAN PETER
1st year Graduate Student, Interdisciplinary Materials Science
PI: Richard Haglund

"Physical Fabrication of Cu_xS Nanoparticles for Enhanced Harmonic Generation"

Harmonic Generation allows for the combination of multiple photons into a single photon of higher energy. Dual plasmonic heterostructures of noble-metal and copper chalcogenide have the great potential to generate the effect, but fabrication was done using a wet chemistry approach that has limited control of both geometry and spacing between nanoparticles. Here, RF Magnetron Sputtering was used to deposit thin films of copper (II) sulfide (CuS) onto a substrate. This was then annealed and thermally decomposed into a different copper sulfides (Cu_xS). Surface characterization was performed using Scanning Electron Microscopy and Contact Angle Goniometry. The deposited material forms nanoparticles on the substrate surface, which compacted into sub 100 nm granules after annealing. These results suggest that physical deposition techniques may be suitable for production of uniform thin layers of Cu_xS nanoparticles.

EMMANUEL KABUOBANYE DABUO
1st year Graduate Student, Interdisciplinary Materials Science
PI: Josh Caldwell

"Correlative, electroluminescence, and Nano-Optics investigation of extended defects in wide band gap semiconductors"

Wide band gap (WBG) semiconductors like SiC, and GaN, excel over traditional materials (e.g., silicon) in high-power and high-temperature applications. Despite advances in SiC and GaN devices, optimizing efficiency is challenging due to defects. This study examines the characterization of extended defects on device performance using electroluminescence imaging. Additionally, we will assess the effectiveness of scattering-type scanning near-field optical microscopy (s-SNOM) and nano-Fourier transform infrared spectroscopy (nano-FTIR) to obtain relevant information like carrier densities and strain at the length scale of the extended defect. These novel techniques enable nanoscale spatial resolution (~10 nm), offering critical insights into the impact of each type of defect in WBG materials.

DAKOTA BRAATEN
1st year Graduate Student, Interdisciplinary Materials Science
PI: Piran Kidambi

"Investigating the Effect of Monolayer Graphene on Carbonate and Bicarbonate Crossover Through Anion Exchange Membranes"

The development of more advanced membranes is required to prevent the crossover of byproduct ions in Anion Exchange Membrane (AEM) carbon dioxide (CO2) electrolyzers. Specifically, reducing the amount of bicarbonate/carbonate crossover while retaining hydroxide conductivity is required to achieve industry-relevant efficiencies. Monolayer graphene has shown great promise in keeping significant proton conductivity through proton exchange membranes while increasing the selectivity of protons to hydrogen gas. This same principle can be applied to AEMs to maintain hydroxide conductivity while reducing the amount of ionic crossover received from bicarbonate/carbonate ions to considerably increase the efficiency of AEM CO2 electrolyzers.

THIAGO ARNAUD
1st year Graduate Student, Interdisciplinary Materials Science
PI: Josh Caldwell

"Controlling polariton dispersion in anisotropic media through isotopic enrichment"

Phonon polaritons (PhPs) are the quantized coupling between free space photons and phonons within the atomic lattice of a polar dielectric crystal. These PhPs are supported within the spectral region known as the Restrahalen Band, where the real-valued permittivity becomes negative. Hyperbolic phonon polaritons (HPhPs) are polaritonic mode classified within anisotropic crystals where the in-plane permittivity differs from the out-of-plane permittivity. Molybdenum trioxide (α-MoO3) is a natural hyperbolic material that exhibits trifold anisotropy, where there is a different dielectric function for each in-plane direction. Strategically monoisotopically enriching Mo or O in MoO3 offers an avenue to understand the effects of percent change in mass on HPhPs, red or blue-shift the HPhP dispersion, and consequentially tailor the HPhP lifetime and propagation length. Furthermore, the dispersion shift allows for an overlap in polariton active regions that enable the design of polaritonic heterostructures.

JOHN OKOLO
1st year Graduate Student, Interdisciplinary Materials Science
PI: Jason Valentine

"Dielectric Metasurfaces as Optical Resonators: A Computational Approach to Light Confinement and Field Dynamics"

Two-dimensional dielectric metasurfaces, composed of subwavelength structures are widely focused on for their ability to precisely confine and manipulate electromagnetic waves. Their compact form factor allows for the modulation of phase, amplitude, and polarization, which typically require bulky components. In this study, we used Rigorous Coupling Wave Analysis (RCWA) software to investigate how the geometry of the subwavelength structures influences the resonance behavior of light. Through simulations, we demonstrated that compact parameters of the metasurface geometry significantly enhances the resonant response, including electric field localization. These results highlight the importance of geometric tuning in developing high-performance dielectric metasurfaces.

KATELYN DERR
1st year Graduate Student, Interdisciplinary Materials Science
PI: Sharon Weiss

"Innovative Porous Silicon Biosensor Design with Fluidic Control Using Sodium Polyacrylate"

Porous silicon (PSi)-on-paper was recently reported as a promising new biosensor platform for highly sensitive, quantitative, and easy to use rapid diagnostic tests. However, challenges achieving the anticipated high detection sensitivity and a longer than expected response time must be addressed for this platform to demonstrate its full potential. This work reports on two key materials advancements that improve the detection sensitivity and response time of the PSi-on-paper biosensor: (1) incorporation of polypropylene on paper to extend the analyte exposure time to the biosensor and (2) incorporation of sodium polyacrylate in a superabsorbent pad to reduce the PSi drying time.