NanoDay!

Daniel Woods
Biomedical Engineering, Graduate Student
Daniel Gonzales Research Group

"Flexible Microelectrodes for Acute Recording in Nonhuman Primates"

The rigidity of state-of-the-art silicon electrophysiology probes compromises stable long-term recordings in the brain's soft tissue. Flexible polymer-based probes offer superior mechanical compliance and biocompatibility, enabling more robust data collection. Their transparency also enhances optogenetic applications. Our probes, fabricated with Parylene-C and a platinum conductive layer, have a contact impedance of ∼1 MΩ. We developed novel implantation methods to provide reliable, robust extracellular electrophysiology of cortical neurons in both rodents and Nonhuman Primates (NHP). Preliminary NHP recordings during working memory tasks captured both local field potential and spiking activity in the prefrontal cortex. This chronic implementation is expected to reduce the inflammation and foreign body response that silicon probes have yet to overcome. This successful integration of flexible electrodes with behaving NHPs marks a breakthrough for in vivo electrophysiology.

Yi Zhu
Mechanical Engineering, Graduate Student
Xiaoguang Dong Research Group

"Magnetic soft robotic valve for minimally invasive therapy of gastroesophageal reflux disease"

Sphincter dysfunction contributes to various diseases, notably in gastroesophageal reflux disease (GERD). Current GERD treatments are limited by side effects, invasive surgical implants, risk of nerve injury, and complications such as dysphagia. To overcome this challenge, we report a magnetic soft robotic valve for minimally invasive treatment of sphincter dysfunction. The valve employs soft, magnetic, ring-shaped lattice structures that attract each other to form a robust seal, preventing leakage under external pressures exceeding 7.5 kPa, well above typical gastric reflux pressures (3.2 kPa). On-demand valve opening is enabled via a wearable magnetic actuation system, ensuring controlled passage of food. The device withstands radial forces exceeding 3.5 N during simulated peristalsis and is validated through delivery, sealing, and solid-passage tests in esophageal phantom and ex vivo sheep models and visualized using X-ray imaging. Thus, the proposed method is promising for enabling early, minimally invasive intervention for gastrointestinal and other organ disorders.

Cole Patterson
Physics & Astronomy, Undergraduate Student
VINSE Tech Crew

"Oxide Demonstrations in Atomic Layer Deposition"

The Picosun R200 Advanced Plasma-Enhanced Atomic Layer Deposition (PE-ALD) system, often used in microchip fabrication for highly pure, controlled, and conformal material deposition, presents an exciting opportunity for nanofabrication in the Vanderbilt Institute of Nanoscale Science and Engineering (VINSE) Cleanroom. This research compares film uniformity, roughness, and thickness control between the until-recently non-functional ALD system and similar deposition methods such as Al2O3 sputter deposition (AJA ATC-2200) and SiO2 plasma-enhanced chemical vapor deposition (Trion Orion II). Surface roughness, refractive index, and deposition rate of ALD trimethylaluminum-sourced Al2O3 were also investigated as functions of substrate temperature, film thickness, and oxygen source to better understand the effects of ALD process parameters. Using this data, two high-k MOS capacitors were produced with p-type silicon substrates, sputtered aluminum contacts, and 100 and 5 nm each of ALD Al2O3 as gate oxides. The devices demonstrated uniform capacitances, with no shorting within the tested voltage range. As a final exercise, layers of ALD TiO2, Al2O3, and PECVD SiO2 were deposited on 1.8 μm-wide silicon pillars and imaged using STEM-EDS, visually demonstrating the consistency and conformality at which atomic layer deposition excels.

Emma Bartelsen
Interdisciplinary Materials Science, Graduate Student
Josh Caldwell Research Group

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

Non-dispersive infrared (NDIR) sensors are widely used for gas detection, but typically rely on single-band filters, restricting measurement to one absorption mode and limiting performance. Here we present multi-band thermal emitters, tuned to multiple absorption modes of the target analyte, allowing for a filterless NDIR approach with enhanced sensitivity and selectivity in comparison to traditional NDIR systems. Using an inverse design algorithm, we designed Tamm-plasmon supporting aperiodic distributed Bragg reflectors (a-DBRs) that yield emission peaks aligned with analyte absorption modes. A dual-band emitter for C₃H₈ demonstrates enhanced performance compared to traditional single-band NDIR systems, while two single-band CO and CO₂ emitters highlight the ability to engineer Q-factors for selective detection due to their spectral proximity. As planar thin-film devices, these emitters provide a low-cost and scalable alternative to lithography-dependent wavelength selective technologies.

Sk Md Zli Zaker Shawon
Chemical & Biomolecular Engineering, Graduate Student
Shihong Lin Research Group

"Development of High-Performance Prussian Blue Analogue (PBA) Electrode for Ammonium Ion Recovery from Wastewater"

Ammonium (NH₄⁺) recovery from wastewater is critical for both environmental protection and resource sustainability, as wastewater streams can contain 100–2000 mg/L of NH₄⁺—equivalent to approximately 13.4% of global nitrogen fertilizer usage. Electrochemical separation techniques offer several advantages for this application, including high ion selectivity, low chemical consumption, and operational tunability. These benefits make them attractive alternatives to conventional methods, which often suffer from membrane fouling, high reagent demand, and limited selectivity. However, challenges such as poor long-term stability and degradation of electrode materials still hinder their widespread adoption. To address these limitations, we developed a high-performance Prussian Blue Analogue (PBA) intercalation electrode for capacitive deionization (CDI). Specifically, we engineered a nickel-modified copper hexacyanoferrate (CuNiHCF) electrode that mitigates the degradation issues commonly observed in pristine CuHCF, which, despite its selectivity, lacks long-term cycling stability. Structural and electrochemical analyses reveal that nickel incorporation strengthens the framework’s mechanical integrity, suppresses copper dissolution, and introduces additional redox-active sites, enhancing both selectivity and durability. CuNiHCF exhibits an ammonium-over-sodium selectivity of around 60, a value significantly higher than the 3 to 30 range reported for other electrode types, which typically retain 85% stability at low selectivity (∼3) and only 40% at high selectivity (∼30). In contrast, CuNiHCF retains 81% of its selectivity after 10 cycles. Furthermore, it maintains 75% capacity retention and reduces copper leaching by 50%, while requiring just 10 kWh/kg for NH₄⁺ recovery. These results position CuNiHCF as a robust and energy-efficient electrode material for scalable wastewater treatment and sustainable ammonium recovery.

Will Graham
University of Tennessee Space Institute, Graduate Student
Jacqueline Johnson Research Group

Jacob Schulman
Biomedical Engineering, Graduate Student
John T. Wilson Research Group

"A Molecularly Defined Polymeric Platform for Environmentally Responsive Activation of STING to Enhance Cancer Immunotherapy"

The stimulator of interferon genes (STING) pathway is a promising immuno-oncology target. Despite their potential, STING agonists have yielded underwhelming results in clinical trials due to pharmacological barriers that limit their safety and efficacy. Herein, we describe the design and pre-clinical evaluation of a polymer-dimeric amidobenzimidazole (diABZI) STING agonist conjugate platform for cancer immunotherapy. Central to our technology is a stimuli-responsive diABZI-functionalized RAFT polymerization chain transfer agent (CTA) that allows well-defined polymer chains to be grown directly from a single STING agonist. Using a biocompatible poly(N,N’-dimethylacrylamide) polymer as a first-generation scaffold and a disulfide as a clinically relevant linker, we demonstrate that polymer-STING agonist conjugates liberate diABZI under reducing conditions to trigger STING activation in tumors, thereby stimulating antitumor immunity in multiple murine tumor models and synergizing with α-PD-1 immune checkpoint blockade.

Matthew Vasuta
Interdisciplinary Materials Science, Graduate Student
Kane Jennings Research Group

"Quantifying the Effect of Crosslinking and Hydrophilic Functionality in Polar Solvent Dehydration Using Spin Coating Ring-Opening Metathesis Polymerization"

Samuel Nimmer
Chemistry, Graduate Student
Janet Macdonald Research Group

"Preparation of Nanoparticle Assemblies for Plasmonic Harmonic Generation"

Sahpar Ozer
Mechanical Engineering, Undergraduate Student
VINSE Tech Crew

"Thin, Fast, and Conductive: Production of Graphene Circuits for Education and Innovation"

Graphene’s exceptional electrical, mechanical, and optical properties make it an ideal material for a wide range of applications. From electrical transport to medicine, electronics to defense, graphene is already transforming multiple industries, and this is only the beginning. Yet, its accessibility for students remains limited due to fabrication complexities. This project focuses on fabricating reusable electrical graphene devices that are both durable and suitable for outreach use among students of various age groups, with the goal of expanding both exposure to and accessibility of high-quality graphene for educational and experimental purposes. These devices are intentionally designed to demonstrate two of graphene’s most compelling properties, its exceptional electrical conductivity and optical transparency, enabling learners to directly observe how an advanced material can be applied in functional and visually engaging technologies. By employing chemical vapor deposition (CVD) which decomposes methane gas to deposit graphene onto copper substrates in a cleanroom tube furnace, this project achieves reproducible, high-quality graphene growth verified through Raman spectroscopy and electrical testing. Over the summer, this project was started with growing graphene and fabricating simple resistor devices using aluminum electrodes to effectively highlight graphene’s conductivity and transparency. More recently, a Cu test device with larger electrode pads was introduced to improve device durability and facilitate broader testing. Future work may explore flexible substrates such as parylene. These reusable devices will facilitate hands-on experimentation and outreach, providing practical tools to integrate graphene technology into educational settings and inspire ongoing innovation.

Jojo Pearson
Interdisciplinary Materials Science, Graduate Student
Leon Bellan Research Group

"Development of an Engineered Model of Neurovascular Coupling: GABAergic Interneuron Nitric Oxide Production"

An estimated 65 million people globally suffer from either Alzheimer’s disease (AD) or Parkinson's disease (GBD, 2024). Much of the cognitive decline associated with these and other neurodegenerative diseases is thought to be associated with dysfunctional neurovascular coupling (NVC) (van der Heide, 2022). NVC refers to the complex biochemical signaling that links neuronal activity to modulation of nearby resistance vessel diameters (and thus local vascular resistance). Several studies have identified nitric oxide (NO) as playing a key role in multiple NVC pathways. Indeed, one of the most established signaling pathways involves glutamate (Glu) binding to the N-methyl-D-aspartate receptor 1 (NMDA-R1) of GABAergic interneurons containing nitric oxide synthase (nNOS), a protein which can then convert L-Arginine to N Hydroxy-L-Arginine to form L-Citrulline and NO (Habib, 2011). Once released, NO has strong local vasodilation effects through activation of soluble guanylate cyclase in smooth muscle cells (Van Mil, 2002). This interaction increases local blood flow as neuronal activity increases. While many microphysiological models of the neurovascular unit have been previously demonstrated, to date no one has focused on this crucial process. As a step towards a microphysiological model of NVC, we aim to replicate the pathway described above. After validating the presence of nNOS and NMDA-R1 in the human iPSC-derived GABAergic interneurons we must also determine if Glu stimulation induces the production of NO in these neuron populations.

Sarah Hall
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"ROS-responsive Co-loaded Nanoparticles for the Treatment of Tumor-Induced Bone Disease"

Tumor-induced bone disease (TIBD), when breast cancer cells metastasize to bone, occurs in 73% of metastatic breast cancer patients. In the bone, cancer cells are chemoresistant partially due to elevated levels of Gli transcription factors. To improve treatments, we have developed polymeric nanoparticles (NPs) that encapsulate a Gli inhibitor, HPI-1, and the chemotherapy Paclitaxel (PTX). The NP system is comprised of ABA triblock copolymers that possess a tunable, ROS-triggered release mechanism. By co-delivering these drugs, we expect to inhibit Gli and re-sensitize tumor cells to chemotherapy. Current work includes characterization of the co-loaded NPs, including loading efficiency, morphology, and size. Additionally, we have seen that the co-loaded NPs more robustly inhibit cell growth compared to individual drugs in spheroids. Our next step is to evaluate the efficacy of these co-loaded NPs in vivo.

Zachary Martin
Electrical & Computer Engineering, Graduate Student
Sharon Weiss Research Group

"Colorimetric Smartphone Sensing on a Porous Silicon Platform"

Mia Woodruff
Biomedical Engineering Graduate Student
John T. Wilson Research Group

"Albumin-based carriers for inducing antigen-specific tolerance in EAE"

Multiple sclerosis (MS) is a chronic, inflammatory disease of the central nervous system (CNS) that affects over 2.8 million people worldwide. This disorder is characterized by an autoimmune-mediated attack on the myelinated axons, resulting in neurodegeneration and neurological disability. Current treatments for MS widely suppress T-cell and B-cell populations as well as their egress into the CNS, such as anti-CD20 antibodies and S1P inhibitors. With the chronic administration of these medications, patients typically suffer from immunosuppression and an increased infection risk. Here, we have developed albumin-based carriers for antigen-specific immunotherapy that can selectively tolerize autoreactive lymphocytes and minimize immunosuppression. Albumin has many tolerogenic properties due to its role in maintaining osmotic pressure in the blood; namely, it is highly expressed, non-inflammatory, and has a long half-life. We hypothesize that attaching antigens to albumin will extend their circulation time, thereby increasing exposure to antigen-presenting cells in a non-inflammatory context, creating the ideal environment for inducing immune tolerance. Our team has designed tolerizing immunotherapies for MS by labeling albumin with myelin-specific antigens in vitro (MSA-MOG) or in situ (nAlb-MOG). In experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, prophylactic treatment with MSA-MOG or nAlb-MOG was sufficient to limit immune cell infiltration into the CNS, prevent myelin loss, and completely inhibit disease onset.

Rahul Shah
Interdisciplinary Materials Science, Graduate Student
Jason Valentine Research Group

"Optimized metasurface filters for angle-robust, high resolution, real-time on-chip hyperspectral imaging in the SWIR"

Grace Adams
Biomedical Engineering, Graduate Student
Daniel Gonzales Research Group

"Flexible, semi-transparent microelectrode arrays for simultaneous electrophysiology and two-photon imaging"

Riyanka Narasimhan
Biochemistry & Chemical Biology, Undergraduate Student
Craig Duvall Research Group

"Shear-Thinning Synthetic Polymer-Based Hydrogel Microparticles for Allogeneic Cell Delivery"

Allogeneic cell-based therapies can provide paracrine effects to remedy a variety of disease conditions, but their effectiveness and longevity can be limited by cell destruction due to host immune response. Hydrogels can be used to encapsulate therapeutic cells to protect them from host destruction. To better allow for the diffusion of oxygen and nutrients to the cells and to allow for paracrine factor release and bioavailability to the host, hydrogel encapsulation approaches can benefit from the utilization of aggregates of microgels rather than bulk hydrogel materials. Herein, we describe new synthetic polymer, norbornene-based HMPs as potential candidates for cell encapsulation and further development into an injectable platform for allogeneic cell therapies.

Emily Byrum
Interdisciplinary Materials Science, Graduate Student
David Kosson & Florence Sanchez Research Groups

"3D Printing of Electric Arc Furnace Slag Geopolymer Cement with Nano Additives"

Adam Abdulrahman
Biomedical Engineering, Graduate Student
Ethan Lippmann Research Group

Elizabeth Hays
Interdisciplinary Materials Science, Graduate Student
Janet Macdonald Research Group

"Role of kinetics vs thermodynamics in the colloidal synthesis of ZnSe polymorphs"

Metal chalcogenide polymorphs exhibit unique properties for different applications, yet the mechanisms behind crystalline phase formation are not well understood. Previous work has studied the effect of reaction kinetics on phase determination of different metal selenide polymorph families using amine and carboxylic acid ligands of varying chain lengths. When looking at the ZnSe system, however, an unexpected trend occurs, where a larger ligand corona results in the formation of thermodynamic ZnSe. Here, in situ small- and wide-angle X-ray scattering (SAXS/WAXS), powder X-ray diffraction (pXRD), and high-resolution transmission electron microscopy (HRTEM) are used to further understand the role of kinetics in determining polymorphism at early stages of nucleation.

Sarah Saleh
Chemistry, Graduate Student
David Cliffel Research Group

"The Electrochemical Reduction of Carbon Dioxide with Photosystem I"

Eden Teo
Electrical & Computer Engineering, Undergraduate Student
Sharon Weiss Research Group

"Radiation-Induced Gain Degradation of Silicon Avalanche Photodiodes in the Space Environment"

Brennen Thomas
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"OA Targeting Peptide-siRNA Conjugates for Improved Delivery to the Joint Space"

Huijin An
Interdisciplinary Materials Science, Graduate Student
Sharon Weiss Research Group

"Flow-rate Tunable Paper Microfluidics for Signal Enhancement in Porous Silicon Biosensor"

A paper-based biosensor has been developed that integrates a functionalized porous silicon (PSi) membrane as the active sensing element for quantifiable detection. For exposures to the analyte, improved molecular transport in the PSi membranes on paper leads to larger signal changes than traditional PSi films that remain on a silicon substrate. In this work, we discuss controlling the incubation time of the analyte and overall testing time by incorporating different channel widths of microfluidic paper and absorbent pad beneath the PSi membrane. The PSi-on-paper sensor platform has the potential to serve as an effective, low-cost, rapid diagnostic test with highly sensitive, quantitative readout for a wide range of analytes.

Nina Cassidy
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"Albumin-binding siRNA conjugates targeting Mcl-1 for the treatment of Triple-Negative Breast Cancer"

Ruijian Ge
Mechanical Engineering, Graduate Student
Xiaoguang Dong Research Group

"A Wireless Implantable Sensory Ring for Continuous Airway Stent Migration Tracking"

Kieran Nehil-Puleo
Interdisciplinary Materials Science, Graduate Student
Peter Cummings Research Group

"Grouper: symmetry-aware functional-group graph representations for generative exploration of chemical space"

The vastness of chemical space holds immense potential for discovery, yet its systematic exploration remains computationally daunting. We mitigate this complexity by focusing on chemically meaningful differences captured by functional‑group motifs and collapsing symmetry‑equivalent configurations. We operationalize this principle with a symmetry‑aware, hierarchical representation of molecules composed of functional groups. Combined with combinatorial and algebraic methods, this enables efficient generation and analysis of chemical spaces. Because isomorphism checks dominate the computational cost of graph generation, incorporating graph and group symmetries yields substantial efficiency gains. The symmetry-aware random and exhaustive methods consistently outperform the naïve approach, achieving up to a two-order-of-magnitude reduction in isomorphism checks near the exhaustive limit. The resulting computational savings, together with scalable, parallel code, give access to previously untenable strategies such as exhaustive design, verified via Pólya theory. This framework ensures interoperability across simulation formats and data-driven models, enabling end-to-end molecular design (generation, characterization, and analysis). We demonstrate its utility in solubility optimization and polymer functionalization, opening pathways to synthetically meaningful, computationally tractable discovery pipelines.

Avanelle Stoltz
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"A Cationic, ROS-responsive Polymer for siRNA Conjugation for Delivery in vivo"

Small interfering RNA (siRNA) has been proven as a promising therapeutic for treatment of various disease states, but delivery of siRNA has been a challenge due to endosomal entrapment. Our group has synthesized a library of novel cationic, ROS-responsive polymers for complexing with siRNA to facilitate endosomal escape and delivery as a polyplex system. The parent co-polymers were synthesized using a ring-opening polymerization of propylene sulfide (PS) or a 50/50 copolymerization of PS and PS-tert-butyldimethylsilyl at different molecular weights. After polymerization, the ROS-responsive amine group di-methyl was then grafted onto the parent polymer via Carbonyldiimidazole addition. Polyplexes were formed at varying N:P ratios and evaluated via DLS, zeta potential, siRNA encapsulation efficiency, and in vitro cell uptake and knockdown. Further characterization will include endosomal escape characterization, ROS-responsiveness, and siRNA retention.

Youn Jae Jung
Chemical & Biomolecular Engineering, Postdoctoral Scholar
John T. Wilson Research Group

"Scalable Platform to Produce Extracellular Vesicles with Efficient RNA Loading"

Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have emerged as promising carriers for RNA-based therapeutics. However, scalable production and efficient RNA loading remain critical challenges for the therapeutic use of MSC-EVs. In this study, we present a tunable system for engineering MSCs to produce RNA-containing EVs through inducible overexpression of vesicle-associated membrane protein-associated protein A (VAP-A). Using a cumate-inducible expression system in hTERT-MSCs, we demonstrate dose- and time-dependent upregulation of VAP-A. Upon induction, VAP-A overexpressing MSCs secrete significantly increased quantities of both small and large EVs, with a marked enhancement in RNA amount in EV compared to parental cells. EVs were isolated via iodixanol gradient ultracentrifugation and characterized by TEM, Western blotting for EV markers, and nanoparticle tracking analysis (NTA). Moreover, we employed a scalable platform, a hollow fiber bioreactor system, which exhibited improved yield and RNA payload compared to 2D cultures. To evaluate the function of RNA in EVs, we employed a pre-miR-451 backbone system as a reporter system to load siRNA in EVs for EV-mediated siRNA gene silencing in recipient cells. We will employ this reporter system for siRNA delivery to recipient cells via EVs, evaluating the therapeutic potential of these engineered EVs for further studies. These findings establish VAP-A as a key modulator of EV biogenesis and RNA packaging, providing a scalable strategy for manufacturing functional RNA-loaded EVs for therapeutic applications.

Mark Mc Veigh
Interdisciplinary Materials Science, Graduate Student
Leon Bellan Research Group

"Understanding the Compatibility of Fluoride-Based Radiopharmaceutical Reaction Solutions and PDMS"

Microfluidic production of radiopharmaceuticals has the ability to change the paradigm of nuclear medicine manufacturing and enable the transition to personalized radiotheranostics. Several early and contemporary designs of these systems use PDMS as the microfluidic device material. Still, there is conflicting evidence within the literature as to the existence and extent of an incompatibility between fluoride-based reaction solutions (the most common type of reaction solution for radiopharmaceutical production) and PDMS. This work uses several analytical techniques to directly probe the interaction between these components, confirm the reactive relationship between them, and suggest a mechanism which unionizes the seemingly conflicting conclusions of previous reports.

Hayden Pagendarm
Biomedical Engineering, Graduate Student
John T. Wilson Research Group

"Systemic cancer vaccination by albumin-binding nanobody-antigen fusions and immunostimulatory drug conjugates generates CD8+ T cells and inflames the tumor microenvironment"

Personalized cancer vaccines hold immense promise for the treatment of various cancers. Peptide cancer vaccines utilize novel antigen (neoantigen) epitopes (~2 kDa) that are presented by major histocompatibility complexes (MHCs). Unfortunately, the efficacy of peptide neoantigen 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 neoantigen delivery using a nanobody (Nb) targeting mouse serum albumin (MSA) (nAlb) and co-administered it with an innate immune agonist (diABZI)-nAlb conjugate (nAlb-diABZI) to generate robust, neoantigen-specific T cells.

Richarda Niemann
Mechanical Engineering, Postdoctoral Scholar
Josh Caldwell Research Group

Amelia Soltes
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"Development of siRNA Nanoparticles for Osteoarthritis Treatment"

Emma Endres
Chemistry, Graduate Student
Janet Macdonald Research Group

"Phase Pure Synthesis and Characterization of Colloidal Smythite (Fe3+xS4)"

For the first time we report the synthesis of pure colloidal smythite (Fe3+xS4) nanocrystals. Utilizing 1,4-bis(diphenylphosphino)butane as a directing agent at a moderate temperature of 195 °C, crumpled nanosheets of smythite were synthesized. The phase purity and morphology were confirmed via powder X-ray diffraction (pXRD), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). As naturally occurring smythite has been shown to have magnetic properties, the pure synthetic smythite was further characterized via a superconducting quantum interference device (SQUID). The phase stability was also characterized via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and variable temperature pXRD.

Joshua McCune
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"Scaffold Mediated Delivery of siRNA for Accelerated Wound Healing"

Thiago Arnaud
Interdisciplinary Materials Science, Graduate Student
Josh Caldwell Research Group

"Unveiling the phonon driven responses in isotopically enriched MoO_{3}"

The implementation of polaritonic-mediated processes into nanoscale devices require a broad platform of material choices and tuning parameters to realize a desired spectral, spatial, temporal, or thermal response. α-MoO3 is a popular hyperbolic crystal that displays different optical responses along each of its crystallographic directions. The intrinsic optical behavior of α-MoO3 translates into three tunable dispersions of hyperbolic phonon polaritons (HPhPs) that are highly susceptible to substrate mediation, geometric confinement, and excitation conditions to name a few. Here, we investigate the optical and thermal response of isotopically enriched α-MoO3: 98MoO3, Mo18O3 and 98Mo18O3. We report the effects of O18 enrichment resulting in far field spectral redshifts of ~5% in both Raman and IR-active TO phonons and similar near field responses by probing HPhPs with s-SNOM. The HPhP Q-factors of the fundamental mode were extracted for each sample, revealing a maxima Q-factor increase of ~50% in the RB2 and ~130% along the [001] in the RB3 due to a higher confinement of free space light and lower phonon scattering rates in 98Mo18O3. We highlight the first experimental observation of higher-order modes propagating in single slabs of isotopically enriched α-MoO3. Lastly, we briefly discuss the measured in and out-of-plane thermal conductivity values in all our isotopic samples to be on the order of 10 W m-1 K-1 and 2 W m-1 K-1 respectively. This work establishes the breadth of tuning HPhP excitation frequencies, confinement factors, and Q-factors through isotopically enriched α-MoO3 and expands our material database to engineer novel 2D material photonic devices.

Sydney Henriques
Biomedical Engineering, Graduate Student
Todd Giorgio Research Group

"Targeted siRNA Delivery via Mannosylated Nanoparticles to Modulate Macrophage Behavior in Cancer"

Modulation of Nuclear Factor Kappa-B (NF-kB) signaling can reprogram macrophages in the proximal tumor microenvironment from a pro-tumor to an anti-tumor phenotype. The canonical NF-kB pathway is rapidly activated and drives inflammatory, M1-like macrophage functions, whereas the non-canonical NF-kB pathway has been associated with tumor progression. In this work, we employ mannosylated polymeric nanoparticles loaded with targeted siRNAs to modulate these pathways in models of breast and ovarian cancer. By either activating canonical NF-kB or inhibiting non-canonical NF-kB, we achieve anti-tumor responses in both primary and metastatic sites. These results highlight NF-kB pathway modulation as a promising macrophage-targeted strategy for cancer immunotherapy.

Praise Eromosele
Chemical & Biomolecular Engineering, Graduate Student
Kane Jennings Research Group

"Nanoscale Photosystem I–Polymer Composite Films for Improved Protein–Electrode Wiring"

Photosynthetic proteins such as Photosystem I (PSI) offer a model for highly efficient solar energy conversion. However, when immobilized on gold electrodes, photocurrent generation is limited by poor electronic coupling. In this work, we demonstrate a method for fabricating nanoscale PSI–polymer composite films that bridge the gap between PSI’s buried redox cofactors and the electrode surface. Using cyclic voltammetry, conductive polyaniline (PANI) was electropolymerized around a PSI monolayer immobilized on a gold electrode. Ellipsometry and FTIR confirm polymer deposition and structural retention of PSI within the composite films, while photochronoamperometry reveals a marked enhancement in photocurrent. This study validates the feasibility of fabricating functional nanoscale PSI–polymer composite films through controlled electropolymerization.

Emmanuel Dabuo
Interdisciplinary Materials Science, Graduate Student
Josh Caldwell Research Group

"Developing SNOM and Nano-FTIR for Nanoscale Defect Characterization in Wide-Bandgap Semiconductors"

The continued drive toward device miniaturization has intensified the demand for wide-bandgap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN), known for their superior breakdown voltage, high switching speeds, and excellent performance in high-frequency and high-temperature applications. However, nanoscale defects—often undetectable by conventional metrology techniques—adversely affect the performance of these devices. This work explores the development of scattering-type scanning near-field optical microscopy (s-SNOM) and nanoscale Fourier transform infrared spectroscopy (nano-FTIR) as advanced, non-destructive tools for defect characterization in these materials. By combining high spatial resolution with optical and vibrational sensitivity, these techniques offer new pathways for understanding and mitigating these defects.

Rafael Aguilar Rodas
Electrical and Computer Engineering, Undergraduate Student
VINSE Tech Crew

"Fabrication Developments of Quantum Photonic Integrated Circuits"

Quantum Photonic Integrated Circuits based on novel ferroelectric thin films offer an opportunity to combine the advantages of silicon photonics (CMOS compatibility), those of traditional quantum systems (superposition/ entanglement) either higher order electro-optical responses. To leverage the recent advances done at ORNL in AlN and BaTiO3 synthesis and tunability via magnetic domain poling of these thin films it was necessary to adapt traditional silicon photonics fabrication to this new material system. In this poster effects of metal masks on sidewalk roughness, angle and shadow masking are discussed.

Madisen Domayer
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"Creation of Hyaluronic Acid Hydrogel 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.

Ke-Sean Peter
Interdisciplinary Materials Science, Graduate Student
Josh Caldwell Research Group

"Photoluminescence Confocal Microscopy & Single Photon Detection"

Single photons emitters (SPEs) are pushing the world towards a quantum based reality. Quantum cryptography, computing, and communication demand efficient and reproducible quantum light sources. While generating quantum light sources (SPEs) is an active area of research, reliable methods for verifying their quantum nature are equally essential. Confocal microscopy combined with a Hanbury Brown–Twiss (HBT) interferometer offers a laboratory-based solution for locating photoluminescent emitters and confirming their single-photon emission. We present our new free-space confocal microscopy system with integrated HBT and spectrometer capabilities for detecting and characterizing SPEs in solid-state materials , With this setup we obtain first results on proof-of-concept emitter samples.

Patricia Poley
Biomedical Engineering, Graduate Student
Craig Duvall Research Group

"Antioxidant Polymeric Microparticles for the Treatment of Osteoarthritis"

Trey Long
Interdisciplinary Materials Science, Graduate Student
Josh Caldwell Research Group

"Near-field Radiative Heat Transfer across All-solid Separations"

Near-field radiative heat transfer (NFRHT) has emerged as a promising mechanism for nanoscale thermal management. When the separation between two bodies decreases below the peak thermal wavelength, radiative energy transfer can exceed the blackbody limit by several orders of magnitude via evanescent-wave coupling. These enhancements are especially pronounced in systems supporting optical resonances within the frequency range of peak thermal emission such as phonon polaritons. Significant theoretical and experimental progress has been made in recent years, but investigations have focused on vacuum separated interfaces. Here, we explore NFRHT across fully solid-state multilayer systems with SiN separations between emitter and receiver. We present a theoretical framework based on the fluctuation-dissipation theorem and compute the transmission function between two polaritonic slabs separated by lossy, isotropic, non-dispersive medium using the Scattering Matrix Method.

He Zhuo
Chemistry, Graduate Student
Janet Macdonald Research Group

"Phase-control of nickel selenide nanoparticles"

Nickel selenide nanoparticles (NPs) exhibit diverse phase-dependent properties that make them valuable in catalysis, energy storage, and optoelectronics. This work proposes a mechanism-driven study to rationalize and control phase outcomes in Ni-Se NP syntheses. Here we probe how steric and electronic variation in phosphine-selenide precursors regulates selenium delivery and study the influence of diselenide chain length and solvent coordination on nucleation and phase evolution. The anticipated outcome is a set of predictive phase-selection maps linking precursor design and solvent coordination to specific Ni-Se phases, providing transferable strategies for broader metal chalcogenide NPs systems.

Jahnu Saikia
Biomedical Engineering, Postdoctoral Scholar
Craig Duvall Research Group

"Optimized albumin-piggybacking strategy enhances ultra-short peptide delivery and bioavailability in a PTOA mouse model"

LSKL, an ultra-short peptide derived from the Latent Associated Peptide domain, effectively inhibits TSP1-mediated TGF activation, making it a promising therapeutic candidate for ischemic injury, hypertrophic scarring, and fibrosis. However, its rapid systemic clearance limits its clinical utility. To overcome this, we developed an albumin piggybacking strategy by conjugating LSKL to octadecanedioic acid (C18 diacid) via an oligoethylene glycol (OEG) linker, preserving peptide functionality with minimal cytotoxicity. To further enhance bioavailability and reduce aggregation, we designed and evaluated three linker variants: (1) direct conjugation, (2) γ-glutamic acid, and (3) γ-glutamic acid with two OEG units. Bio-Layer Interferometry and Size-Exclusion FPLC identified the optimal C-terminal branching site as Peptide-OEG-OEG-γGlu-C18 diacid, which exhibited strong albumin binding. These lipid-modified peptide variants demonstrated improved pharmacokinetics after subcutaneous injection (t₁/₂ = 52h) and enhanced biodistribution to injury sites in a post-traumatic osteoarthritis (PTOA) mouse model. Our findings present a viable strategy for optimizing the pharmacokinetics and therapeutic efficacy of short peptides, offering potential advancements in regenerative medicine.

John Buchner
Interdisciplinary Materials Science, Graduate Student
Josh Caldwell Research Group

"Dieletric Gap Tuning of Hyperbolic Image Polaritons"

In the infrared, phonon polaritons (PhPs) are a promising platform for sub-diffractional light propagation and manipulation. A specific form, hyperbolic image polaritons utilize metallic substrates under a polaritonic material to mirror the field, anti-symmetrically to the interface, leading increased propagation cycles and confinement, both in and out of plane. Here, we demonstrate the tunability of this effect in a biaxially anisotropic material, MoO3, by introducing a dielectric gap between the metallic and polaritonic material. This allows continuous adjustment, by thickness and material choice, of the polariton wavelength and wavefront shape. Furthermore, the gap material experiences significant electric field enhancements compared to the upper surface even for high-index materials. These advancements help to further our ability to control IR light at the nanoscale and use PhPs to strongly confine fields within non-resonant materials for various applications.

Owen Meilander
Interdisciplinary Materials Science, Graduate Student
Mona Ebrish Research Group

"Advancing GaN Electronics through Substrate Engineering and Integration"

Gallium Nitride (GaN) is a promising next-generation semiconductor material that enables high-speed, high-efficiency electronic devices. In this work, we investigate how different substrate materials influence the performance of GaN high electron mobility transistors (HEMTs). Furthermore, we present a novel transfer technique for the heterogeneous integration of GaN devices onto alternative substrates, enabling improved design flexibility and potential cost reduction. This study highlights the importance of substrate selection and innovative fabrication methods in advancing wide-bandgap electronic technologies.

Youngji Kim
Mechanical Engineering, Postdoctoral Scholar
Josh Caldwell Research Group

"Demonstration of Angle-Dependent Shear Polaritons in β-Ga2O3 Nanostructures for Infrared Nanophotonics"

Phonon polaritons – hybrid quasiparticles formed by coupling between infrared photons and optical phonons – enable deeply subwavelength light confinement with remarkably low losses. In anisotropic low-symmetry materials, such as monoclinic β-Ga2O3 (bGO), the intrinsic shear effect arising from asymmetric phonon dispersion provides an additional degree of freedom for controlling polariton propagation. Recently, hyperbolic shear polaritons (HShPs) in bGO exhibiting frequency-dependent propagation direction and shear-induced mode splitting have been demonstrated. Here, we investigate how the orientation of bGO nanostructures influences their polaritonic resonances. Arrays of bGO nanopillars with identical geometric parameters but systematically rotated in-plane angles were fabricated to probe angle-dependent resonance shifts. Far-field FTIR and numerical simulations reveal distinct spectral shifts in the 700-800 cm-1 range as a function of nanopillar rotation. Preliminary near-field measurements using s-SNOM confirm strong dipole-like resonances at on-resonance frequencies, while off-resonance conditions yield negligible field enhancement. This study provides new insights for engineering of low symmetry materials as active platforms for polarization-sensitive and spectrally tunable photonic devices, advancing the development of next-generation infrared photonic technologies.

Jack Loken
Interdisciplinary Materials Science, Graduate Student
John T. Wilson Research Group

"Fluorescein-Based Polymers for the Regulation of Engineered Cells in Cancer Immunotherapy"

Adoptive cellular immunotherapies, such as chimeric antigen receptor (CAR) T cells and tumor infiltrating lymphocytes (TILs), have revolutionized the traditional cancer treatment paradigm. CAR T cell treatments can induce complete remission in patients with various hematologic malignancies, but struggle with solid tumors due to an immunosuppressive tumor microenvironment and dysfunctional vasculature where cells lose persistence and efficacy. Current clinical applications of CAR T cells rely on endogenous protein markers to target the physiological site of interest and activate native cytotoxic T cell functions. This approach is susceptible to on-target off-tumor activity, systemic toxicity, and T cell dysfunction. Instead, we investigate an exogenous small molecule, fluorescein (Flu), capable of activating T cells engineered with a synthetic notch (synNotch) receptor or synthetic intramembrane proteolysis receptor (SNIPR). Flu is a fluorescent probe used in medical imaging and highly amenable to numerous material design strategies. Our primary approach synthesizes biocompatible polymers via reversible addition fragmentation chain transfer (RAFT) polymerization with reactive groups for post polymerization Flu conjugation. By assembling polymer constructs of varying molecular weight, number of pendant Flu ligands, and macromolecular structure we can efficiently drive receptor signal induction both in vitro and in vivo. Our work aims to shift the landscape of engineered cellular immunotherapies from natural ligands and signaling pathways to a fully customizable cellular response based on designer materials.

Abayomi Opadele
Electrical & Computer Engineering, Postdoctoral Scholar
Justus Ndukaife Research Group

"Artificial Intelligence-Augmented Tracking and Label-Free Characterization of Milk-Derived EVs"

Amanda Gualda
Research Experience for High School Students
Piran Kidambi Research Group

"Designing Reactors for the Synthesis of Conjugated Polymer Frameworks (CPF)"

Water desalination is a vital tool to combat water scarcity, but current desalination methods are too energy intensive with reverse osmosis desalination requiring 8-10 times more energy than traditional surface-water treatment technology. Membrane filtration with conjugated polymer frameworks (CPF) is a promising new method for desalination. CPF membranes have an ideal pore size for blocking hydrated ions while allowing water molecules to permeate. The objective of this project is to build a system that can synthesize CPF membranes using chemical vapor deposition.

James Rowe
Research Experience for High School Students
Leon Bellan Research Group

"Advancement of On-Chip Mixing Capabilities for RAPID, a Microfluidic Radiotracer Synthesis Platform"