bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Hypersectral Sensing of Biological Markers at the Point of Need
Authors: Mukundan Harshini , Snijders Antoine M , Saint-John Brandon , Inman Jamie , Kubicek-Sutherland Jessica , Manore Carrie , Brown James Ben
Published: August 2024

There is an urgent need for truly reagent free and agnostic sensing at the point of need for biological and chemical targets. Indeed, the COVID-19 pandemic has re-emphasized the significant need for truly agnostic diagnostics at the point of need. Whereas highly targeted and tailored diagnostics can help us address a known and anticipated threat, they do not prepare us against the next emerging outbreak. To address the significant challenge of developing truly agnostic diagnostics that can improve situational awareness and guide decision making, our team has looked to spectroscopy as an inspiration for the sensing modality; and innate immunity as an inspiration for the biological process and signatures. All biological molecules emanate spectral signatures along the electromagnetic spectrum, integral information from which can provide insights into processes or signatures more effectively. Therefore, we propose the use of hyperspectral sensing as a modality for accurate diagnosis and detection of signatures. With regards to the biology - innate immunity is a broad, agnostic pathogen sensing strategy that allows for the early recognition of all pathogens – known and unknown – with an associated response. Our team has developed strategies to mimic this response in the laboratory, culminating with the (ongoing) development of a data-science and machine learning enabled effort to unravel the complexity of the immune recognition (host cytokine and chemokine response), allowing for their ability to inform on categories of pathogens/disease. It is important to integrate this knowledge with a point of contact diagnostic approach in order to be able to translate the data into usable diagnostic information. To this end, we are working on developing a hyperspectral approach that measures these signatures without reagents from saliva samples in a few seconds. Charged by a back-end machine learning/artificial intelligence algorithm, our approach uses Pattern’s ProSpectral Sensor that measures signatures across various realms of the electromagnetic spectrum. Data on developing this sensing modality as a diagnostic in real time – challenges and advantages – will be presented.
Micropatterning MXene/TiO2 Nanocomposite Ink for Gas Sensing
Authors: Liu Jinhong , Chen Chen , 夏 胜辉 , Leatt Kyle , Khosla Ajit , Thundat Thomas
Published: August 2024

This work describes the preparation, characterization and micropatterning of MXene (Ti3C2/TiO2) nanocomposite inks. The MXene nanopowder was oxidized to Ti3C2/TiO2 nanocomposite powder by stirring in air for 3 hours using air aging method. The Ti3C2/TiO2 nanocomposite powder was then dispersed into Dimethyl Sulfoxide (DMSO) solvent, and the Ti3C2/TiO2 ink was prepared by using 1% mass fraction of Polyvinylpyrrolidone (PVP) solution as dispersant. The two-dimensional layered nanostructure of MXene and the characteristic peaks of TiO2 were observed by Raman and XRD results. SEM and TEM results show the layered structure of MXene nanoparticles as well as TiO2 nanoparticles with a diameter of about 2 nm on a single layer of MXene. FTIR results confirms that Ti-O bonds and Ti-C bonds indicating that part of Ti3C2 was oxidized to TiO2. The results of Brunauer Emmett Teller (BET) test on Ti3C2/TiO2 nanocomposite ink show that the specific surface area of the ink is 10.7194 m²/g and the maximum adsorption of N2 is 32.039cm3/g. Thermogravimetric analysis (TGA) indicate that Ti3C2/TiO2 exhibited excellent thermal stability, with a mass loss of only 15% at 800°C. In order to achieve the optimal printing effect, plasma surface treatment was carried out on the gold-plated silicon wafers, Polyethylene terephthalate (PET), and glass substrates, which decreases the contact angle of the ink on these substrates. The printing of Ti3C2/TiO2 nanocomposite ink on the substrate using the atomized printing technique with a mask plate enables printing of straight lines with a line width of 5µm. Film thickness can be controlled by adjusting the distance between the printhead and the substrate, as well as the pressure of the atomized printing jet.
Innovative 2D Nanomaterials-Based Electrochemical Microfluidic Sensors for Food Safety and Environmental Ecology
Authors: Sachdev Abhay , Matai Ishita , Kumar Deepak , Kumar Vijyesh
Published: August 2024

2D nanomaterials-infused electrochemical microfluidic sensors mark a paradigm shift in precision sensing technology. Leveraging the unique properties of materials like carbons, transition metal and molecularly imprinted polymers, these sensors redefine the benchmarks for electrochemical sensing with their extraordinary sensitivity, rapid response kinetics, and remarkably low detection limits. The integration of a microfluidic system further enhances their capabilities, providing meticulous control over sample volumes and reaction kinetics, ensuring unparalleled reliability and reproducibility in real-time monitoring applications. This amalgamation of advanced nanomaterials and microfluidic technology not only sets new standards for precision sensing but also opens avenues for transformative applications across diverse fields. In the realm of food safety, these sensors emerge as pioneering tools, offering exceptional specificity for the precise detection of contaminants, pathogens, and spoilage indicators. Their rapid, on-site analysis capabilities revolutionize traditional testing methods, enabling timely interventions and elevating the overall quality assurance in the food industry. Simultaneously, their impact extends to environmental ecology, where the sensors play a crucial role in monitoring pollutants, heavy metals, and environmental stressors in real-time. The compact design and portability of these sensors facilitate on-site environmental monitoring, transcending the limitations of conventional laboratory-based testing and contributing to more sustainable and resilient ecosystems. Beyond their technological prowess, these sensors carry significant societal and economic implications. Their compact and portable nature streamlines on-site analyses, minimizing logistical challenges associated with sample transportation and centralized laboratory facilities. This efficiency not only enhances monitoring processes but also holds the potential to revolutionize resource allocation in sectors reliant on rapid and reliable analytical insights. In essence, 2D nanomaterials-based electrochemical microfluidic sensors represent a transformative leap towards precision sensing, promising a future where safeguarding the integrity of our food supply and ecological systems is seamlessly intertwined with technological innovation.

Figure 1
(Digital Presentation) A Microfluidic Approach for Direct Immobilization of Extracellular Vesicles on Gold Nanoislands for Efficient Detection Using Localized Surface Plasmon Resonance
Authors: Mohammadi Kyana , Raju Duraichelvan , Badilescu Simona , Ghosh Anirban , Packirisamy Muthukumaran
Published: August 2024

Extracellular vesicles (EVs) are crucial for intercellular communication and are potential biomarkers for cancer diagnosis. To improve the detection of EVs, we have developed a platform that uses an ultra-thin film of gold to form gold nanoislands. This platform allows for the direct immobilization of EVs onto the gold nanoislands, using a simple microfluidic device. Detection of the EVs is based on the Localized Surface Plasmon Resonance (LSPR) method. With this innovative approach, we aim to enhance the accuracy and efficiency of EV detection, which could ultimately lead to faster detection and therefore the possibility of an early-stage diagnosis of cancer.

Gold nanoparticles are deposited on glass substrates using physical vapor deposition to create an ultra-thin layer of gold. Annealing the nanoparticle film forms gold nano-islands, which are drops with varying shapes and sizes from solid dewetting. A PDMS microfluidic device with a tapered channel of 200-micron depth and a 4mm diameter collection chamber bonded to gold-coated substrates is used to detect EVs from MCF7. The EVs flow through the channel at a rate of 10 µL/min, and the LSPR spectrum of the gold nanoislands is measured before and after EV immobilization. Changes in the refractive index of the surrounding medium due to the presence of EVs cause a shift in the Au LSPR band, which can be used to detect EVs.

In this study, we will utilize extracellular vesicles (EVs) obtained from a breast cancer cell line (MCF7) that had been grown in a small bioreactor. A simple microfluidic device will be designed and fabricated to evaluate the Localized Surface Plasmon Resonance (LSPR) shift of the gold plasmon band for different EV concentrations. The microfluidic device was chosen due to its high reproducibility, sensitivity, and ability to work with small amounts of EVs. To understand the sensitivity of this platform, a calibration curve will be plotted and compared with the results of other platforms that we have previously studied. To validate the LSPR detection using the microfluidic device, the eluted exosomes from the device will be characterized using TRPS and FESEM techniques.

Overall, our findings will demonstrate the potential of utilizing EVs and LSPR-based microfluidic devices as a promising tool for the detection of EVs and further clinical analysis for cancer diagnosis.
Printable MXene Ink Hybridized with ZSM-5 for Gas Sensing and CO2 Capturing
Authors: 夏 胜辉 , Chen Chen , Liu Jinhong , Leatt Kyle , Thundat Thomas , Khosla Ajit
Published: August 2024

In this work we present preparation, characterization and microprinting of Ti3C2/ZSM-5 ink. Printable inks with a viscosity of 5-6 cP were prepared by ultrasonic dispersion of Ti3C2/ZSM-5 nanopowders in DMSO solvent using 1% Polyvinylpyrrolidone (PVP) as dispersant. Brunauer Emmett Teller (BET) results indicate a type IV adsorption isothermal curve for N2 gas with a type H4 retention ring. The data show that the average pore size of the composite material is 23nm, indicating that the material has a micro-mesoporous structure and exhibits excellent adsorption properties for gas sensing applications. However, the adsorption and desorption curves of CO2 shows hysteresis indicating strong interaction between functional groups on the material and CO2 molecules. This material has high CO2 adsorption performance and desorption hysteresis effect, indicating that it can be directly used for CO2 capture. Thermogravimetric (TGA) analysis showed the thermal stability of the composite, with a mass loss of only 5% at 800℃. Ti3C2/ZSM-5 composite ink has excellent anti-oxidation and dispersion properties. When the pure MXene interlayer void is exposed to air, the Ti element in MXene is easily oxidized to TiO2. The introduction of ZSM-5 not only limits the interaction between the functional groups on the surface of MXene, but also fills the layer gap of MXene, effectively reduces the contact with oxygen, and thus shows good oxidation resistance. No characteristic valence signal of TiO2 was observed in XPS results, which confirmed the effectiveness of the method. In addition, imidazole acid molecular sieve frame strengthened MXene adsorption, will have broad prospect of application in gas sensing field. In traditional printing methods, such as drop casting and spin coating, it is difficult to control the uniformity and roughness of coating thickness, which affects the service life and sensing properties of gas sensors. The use of spray atomization technology can maximize the uniform dispersion of ink, and can control the amount of spray, concentration, height and other parameters to control the thickness and roughness of the coating.
Preparation and Application of Manufactured Electrochemical Sensors for the Multiplexed Detection
Authors: Janegitz Bruno , Silva Luiz , Crapnell Robert , Stefano Jessica , Brazaca Lais , Banks Craig E.
Published: August 2024

Monkeypox is a zoonotic viral infection caused by MKPV (1). This disease causes skin lesions, fever and headache among other symptoms, which appear within a few days after the infection, and can led to the hospitalization of the infected person (2). Herein, we present the first 3D-printed electrochemical bio-device for multiplex analysis, enabling portable detection of the Monkeypox Virus (MKPV). The electrochemical device consists of two working biosensors, an immunosensor, and a genosensor, specifically designed for the detection of the protein A29 (antigen) and the DNA target of MKPV. The electrodes were manufactured using lab-made ultra-flexible conductive filaments composed of carbon black, recycled PLA from coffee capsules, and castor oil as plasticizer. The sensors created through 3D printing technology exhibited good reproducibility and repeatability of analytical responses. Furthermore, both the immunosensor and genosensor demonstrated excellent MKPV detection capabilities, with a linear range from 0.01 to 1.0 µmol L-1 for the antigen and 0.1 to 20.0 µmol L-1 for the DNA target. The biosensors achieved limits of detection of 2.7 nmol L-1 and 29.0 nmol L-1 for the immunosensor and genosensor, respectively. Interference tests conducted with the biosensors demonstrated their selectivity for MKPV. Moreover, analyses of fortified human serum samples showed recoveries close to 100%, confirming the absence of significant matrix effects in MKPV analysis. Therefore, the 3D-printed multiplex device represents a viable and highly promising alternative for on-site, portable, and rapid point-of-care MKPV monitoring.

(1) Shafaati, M., Zandi, M., 2022. State-of-the-art on monkeypox virus: an emerging zoonotic disease. Infection 50, 1425–1430.

(2) Halvaei, P., Zandi, S., Zandi, M., 2023. Biosensor as a novel alternative approach for early diagnosis of monkeypox virus. Int. J. Surg. 109, 50–52.
(Invited) Analytical Validation of Aptamer-Based Blood Drug Measurements Against Clinical Benchmark Methods
Authors: Arroyo Netz
Published: August 2024

The practice of monitoring therapeutic drug concentrations in patient biofluids can significantly improve clinical outcomes while simultaneously minimizing adverse side effects. Although undeniably important to achieve effectiveness, therapeutic drug monitoring remains inconvenient in practice, due primarily to the lengthy process of sample collection, transport to a centralized facility, and analysis using costly instrumentation. Adding to this workflow is the possibility of backlogs at centralized clinical laboratories, which is not uncommon and may result in additional delays between biofluid sampling and concentration measurement, which can negatively affect clinical outcomes. In this talk I explore the possibility of using point-of-care, aptamer-based sensors to minimize the time delay between biofluid sampling and drug measurement. I will discuss analytical validations of aptamer-based blood measurements for two drugs, the antibiotic vancomycin and the antiretroviral drug emtricitabine. We conducted clinical agreement studies comparing the measurement outcomes of electrochemical and optical aptamer-based sensors to the benchmark (1) automated competitive immunoassays for vancomycin monitoring in serum, and (2) liquid chromatography coupled to mass spectrometry detection (LC-MS) for plasma emtricitabine. Our results demonstrate that aptamer-based sensors are selective for the free form of these drugs, and can achieve up to 95% positive correlation and 100% negative correlation with the benchmark assays. Given these results, aptamer sensors offer a promising path for point-of-care drug monitoring that is instantaneous and overcomes current barriers for broad implementation of drug monitoring in clinical settings.
Levodopa Sensing in Human Sweat Using 3D Printed Sensors and a Smartphone
Authors: Glasco Dalton Lee , Sheelam Anjaiah , Ho Nguyen H. B. , Bell Jeffrey Gordon
Published: August 2024

Parkinson’s disease (PD) is one of the leading neurological disorders negatively impacting health on a global scale. Patients diagnosed with PD require frequent monitoring, prescribed medications, and therapy for extended periods as symptom severity worsens. The primary pharmaceutical treatment for PD patients is levodopa (L-Dopa) which reduces many symptoms experienced by PD patients (e.g., tremors, cognitive ability, motor dysfunction, etc.) through the regulation of dopamine levels in the body. Herein, the first detection of L-Dopa in human sweat using a low-cost 3D printed sensor with a simple and rapid fabrication protocol combined with a portable potentiostat wirelessly connected to a smartphone via Bluetooth is discussed. By combining saponification and electrochemical activation into a single protocol, the optimized 3D printed carbon electrodes were able to simultaneously detect uric acid and L-Dopa throughout their biologically relevant ranges. The optimized sensors provided a sensitivity of 83 + 3 nA/µM from 24 µM to 300 nM L-Dopa. Common physiological interferents found in sweat (e.g., ascorbic acid, glucose, caffeine) showed no influence on the response for L-Dopa. Lastly, a percent recovery of L-Dopa in human sweat using a smartphone-assisted handheld potentiostat resulted in the recovery of 100 + 8 %, confirming the ability of this sensor to accurately detect L-Dopa in sweat.
Flexible Graphene-Based Sensors for Electrochemical Analysis of Human Saliva and Sweat
Authors: Pola Cicero , Hjort Robert , Garland Nate , Soares Raquel R. A. , Johnson Zachary , Claussen Jonathan , Gomes Carmen L
Published: August 2024

Flexible carbon nanomaterial sensors offer a low-cost, facile fabrication approach toward producing sensors at an industrial scale for electrochemical sensing. Graphene and carbon nanotube (CNT) based sensors have been studied, with various fabrication methods available, including producing high-quality thin film graphene and CNTs via chemical vapor deposition (CVD). However, CVD is a high-temperature vacuum process that is low-yielding and consequently costly, hindering its implementation into single-use test strip sensors. Other methods, such as inkjet or aerosol printing, are more cost-effective as they print graphene inks obtained from liquid-phase exfoliation of graphite, which can be performed using large batch processing techniques. Additionally, the laser-induced graphene (LIG) technique directly converts sp3 carbon found in carbon-rich substrates, such as polyimide, into conductive sp2-hybridized carbon found in graphene through a laser scribing technique. Saliva and sweat offer promising biological fluids for precision health monitoring and diagnostics due to the non-invasive nature of their sampling (no need for a blood draw at a laboratory or a fingerstick at home) and due to the abundance of medically relevant analytes. Saliva can also be used for monitoring infections such as COVID-19 infection. Herein, we introduce graphene-based flexible sensors fabricated using scalable manufacturing based on aerosol jet printing (AJP) using custom-formulated graphene inks and laser-induced graphene via direct writing. We report a label-free, high-sensitivity, and rapid-response-time graphene-based electrochemical immunosensor for quantitatively detecting the SARS-CoV-2 Spike Receptor-Binding Domain (RBD) as well as SARS-CoV-2 Spike S1 protein. We demonstrate LIG-based electrochemical sensors for real-time monitoring of glucose, lactate, and sodium in sweat, and potassium and lactate in saliva. Different electrochemical methods are used, including amperometric, potentiometric, coulometric, and impedimetric, to quantify the analytes. All these electrochemical sensors were validated in human saliva and sweat and demonstrated to have limits of detection and linear sensing ranges that are relevant to their sensing applications. Flexibility studies were also performed to evaluate the ability of the sensors to operate under stresses caused by bending, such as those that would be encountered by skin and implanted oral sensors. Results demonstrate the utility of AJP-graphene and LIG for rapid and sensitive measurement of biological analytes and pathogen infection as simple methods for scalable production of non-invasive salivary and perspiration (sweat) health sensors.
(Invited) Electrodermal Activity Sensing at Scale
Authors: Thomson Seamus , McDuff Daniel , Sunden Lindsey
Published: August 2024

Electrodes have emerged as powerful tools for sensing various physiological signals, paving the way for a new era of wearable consumer devices that offer in situ measurement and analysis. Electrodermal activity (EDA) sensors are used for evaluating autonomic nervous system activity, wherein changes in EDA are associated with physiological excitation reflecting stress, arousal, and emotional changes. The Fitbit Sense 2 and Pixel Watch 2 are two wearable commercial devices that passively measure EDA using wrist-facing electrodes powering a stress management feature. Descriptive findings of the Fitbit Sense 2 across 10 million hours of continuous EDA data collected from over 16,000 people are herein reported, including real-time population response to Thanksgiving 2022 and the 2023 Super Bowl.
Hybrid Piezoresistive 2D MoS2/PEGDA/PANI Covalent Hydrogels for Wearable Strain Sensors
Authors: Domenici Sara , Crisci Matteo , Gatti Teresa
Published: August 2024

The continuous research on electronics, biocompatible materials and nanomaterials has led to the design of a new generation of wearable devices that can be employed in direct contact with the body of the user, which is attractive for real-time, non-invasive health monitoring1. For the satisfaction of such requirements, hydrogel-based conductive devices are often proposed as promising candidates for these applications, thanks to their softness, flexibility, and biocompatibility.

Here we report the synthesis of conductive hybrid hydrogels containing two-dimensional (2D) MoS2. The nanoflakes are integrated in the polymeric matrix creating an anisotropic structure, which helps to generate mismatch stress for a strain sensing under a certain stimulus2, thus allowing the gel to give an electrical response to pressure. 2D MoS2 nanoflakes were produced via top-down chemical exfoliation3 and were incorporated in the hydrogel through a covalent grafting to the polymeric building blocks by exploiting the prior surface functionalization of the flakes4. The conductivity of the hydrogels was increased with the further incorporation of in-situ polyaniline (PANI), which is a widely used material in biomedical applications as a biocompatible conductive polymer5. The as-obtained hydrogels are characterized through a combination of techniques, whereas their electromechanical properties are investigated via a home-made setup to prove that compression causes an increase in current due to the piezoresistive properties introduced with the incorporation of 2D MoS2 and PANI.

[1] Xie, J. et al. J Electrochem Soc
2020,167, 037541.

[2] Zhang, D. et al. J Mater Chem B
2020, 8, 3171–3191.

[3] Acerce, M. et al. Nat Nanotechnol
2015, 10, 313–318.

[4] Knirsch, K. C. et al. ACS Nano
2015, 9, 6018–6030.

[5] Humpolicek, P. et al. J. Synth Met
2012, 162, 722–727.
Void Evolution on the Li-Solid Electrolyte Interface in Solid-State Batteries: A Parametric Study Under Varied Mechanical and Electrochemical Conditions
Authors: Jiao Junning , Zhu Juner , Li Wei , Fang Ruqing
Published: August 2024

Void growth during the plating and stripping process is an important interfacial phenomenon that hinders the development of Li-metal solid-state batteries (SSBs) because it can potentially result in inter-component delamination or growth of Li dendrites. Behind the void growth is the complex interaction between electrochemistry and mechanics. Voids usually grow from micro- or nanoscale initial imperfections on the Li-solid electrolyte (SE) interface. It is, therefore, important to analyze the stress concentration at the initial void tips, which largely determines the growth/shrinking of the void as well as the consequent changes in the internal resistance and overall battery efficiency. Recently, the development of in situ operando experimental technology has enabled the electro-chemo-mechanical characterization of the void growth phenomenon on the Li-SE interface. In this study, we explore how voids in SSBs evolve with a multi-physics model in COMSOL Multiphysics. Based on this model, we perform a systematic parametric study in the space of the mechanical stack pressure and the applied current density. The simulation results show different deformation patterns and potential failure mechanisms under different combination of stack pressure and current density. To better understand the phenomena, we develop an analytical solution to understand the void deformation induced by the inhomogeneous Li-ion concentration field under stack pressure. This analytical approach offers a complementary and intuitive perspective on the mechanical aspect of our simulation findings. By combining the simulation and analytical solutions, we depict a phase diagram, in which we identify the “safe zone” that will not result in void growth. The new insights of this research hold the promise of guiding the development of stabilized SSB interfaces.
Phase Field Damage Framework for Modeling Thin-Film Silicon Anodes in All-Solid-State Batteries
Authors: Pyo Jaechan , Di Leo Claudio V.
Published: August 2024

Recent advancements in solid electrolyte research have revived interest in the concept of silicon anodes for All-Solid-State Batteries (aSSBs). Tan et al. have recently proposed stable cyclic performance of micro-grain size pure silicon anodes paired with sulfide-based solid electrolytes [1]. This development has opened pathways toward potential aSSBs without encountering dendrite growth issues. This rediscovery of the thin-film a-silicon anodes concept has sparked computational interest in simulating the fracture-chemo-mechanical silicon lithiation mechanism. Understanding chemical reactions during lithiation and crack evolution during de-lithiation processes are intriguing topics. Especially, elastic-plastic deformation coupled with phase-field continuous fracture is crucial in comprehending the underlying physics and enhancing performance of battery cell through reverse engineering approaches.

In this work, we develop a thermodynamically consistent deformation-diffusion-damage coupled framework to model the evolution of dense, thin-film-like a-silicon anodes during lithiation and delithiation. During delithiation, tensile stress develops inside the film as the lithiated film overcomes the initial stack pressure and compressive stress prevalent during lithiation. As tensile stress and strain evolve, randomly distributed weak spots lead to crack nucleation. This fracture occurs throughout the silicon film, forming sharp vertical cracks, and depending on surface conditions along the solid-state electrolyte, some interfacial cracks may emerge, leading to permanent contact loss and resulting in capacity reduction.

From the model, we observed “mud crack” like phenomena, where crack distribution is not controlled by particle’s property, but entire cluster’s thickness matters. While flat model suggests that one that nucleate the crack was weak spots where they make stress concentration over entire body, whether they can evolve into big vertical crack mostly governed by connectivity of such weak spot maps. However, from our interface roughness model, what governs the crack evolution most was not the randomly distributed weak spot, but its geometric relative thickness difference between one another. Due to manufacturing process, perfect interface is hard to be achieved and such geometric irregularity always exist, thus, additive and binder studies along the silicon anode and its interface between sse would be key to achieve long and stable life span for a-silicon based aSSBs.

Reference

[1] Tan, Darren HS, et al. "Carbon-free high-loading silicon anodes enabled by sulfide solid electrolytes." Science 373.6562 (2021): 1494-1499.
Studies on Dual Sputtered CuGaO2 Thin Films
Authors: Bharath Akash Hari , Sundaram Kalpathy B.
Published: August 2024

There has been extensive research conducted on n-type transparent conducting oxide (TCO) films like Sn-doped In2O3 (ITO) [1], Al-doped ZnO (AZO) [2], etc. P-type transparent conducting oxides are yet to be researched extensively. Active devices such as p-n junction devices and transistors are required to make progress in the development of transparent electronics. In this effort, research in p-Type TCOs is important. Most of the p-Type TCOs are copper-based ternary oxides [3].

In this work, CuGaO2 thin films were prepared using the dual-target RF magnetron sputtering technique. Cu2O and Ga2O3 targets were simultaneously sputtered on quartz substrates. The sputtering power of Cu2O was kept constant at 50 W and the sputtering power of Ga2O3 was varied. The films were deposited at room temperature and were subsequently annealed in nitrogen ambiance at 900 °C. The X-ray diffraction and optical studies were performed to analyze the films to optimize their properties.

[1] Fallah, H.; Ghasemi, M.; Hassanzadeh, A.; Steki, H. The effect of annealing on structural, electrical and optical properties of nanostructured ITO films prepared by e-beam evaporation. Mater. Res. Bull. 2007, 42, 487–496

[2] Shantheyanda, B.P.; Todi, V.O.; Sundaram, K.B.; Vijayakumar, A.; Oladeji, I. Compositional study of vacuum annealed Al doped ZnO thin films obtained by RF magnetron sputtering. J. Vac. Sci. Technol. A 2011, 29, 051514.

[3] Sundaresh, S.; Bharath, A.H.; Sundaram, K.B. Effect of Cu2O Sputtering Power Variation on the Characteristics of Radio Frequency Sputtered p-Type Delafossite CuCrO2 Thin Films. Coatings 2023, 13, 395.
Advanced Alkaline Amine Fuel Cell Development
Authors: Rose Jackson , Shurtleff Kevin
Published: August 2024

Today, perhaps the most pressing issue is that of power generation. It is important that a source which is inexpensive, reliable, efficient, sustainable, and carbon free be developed and implemented. The hydrogen fuel cell is one possibility. Fuel cells meet many of the requirements listed above save one, current designs are expensive. The catalysts used in most modern hydrogen fuel cells are often platinum group metals, which significantly increases the cost of manufacturing. The high price has proved a significant barrier to adoption.

Alkaline fuel cells are comparatively cheap as the catalysts are inexpensive, but they suffer from reliability issues. For one, they form carbonates, which are produced when carbon dioxide reacts with the potassium hydroxide electrolyte. Carbonates build up on the catalytic sites, rendering the fuel cell inoperable. With this project, the chemistry is being manipulated to eliminate this failure. The standard electrolyte is being replaced with an organic amine. Carbonates are soluble in amines and will not precipitate out of solution. This will prevent the buildup and may clean catalytic sites.

This project is also testing low-cost production processes. We are using electrochemical synthesis methods to deposit nickel and silver onto carbon cloth to build the fuel cell electrodes. These are then characterized via SEM, EDAX, and x-ray fluorescence. The purpose of this is to establish what size of particles will afford the maximum catalytic activity. Optimizing particle size will help to improve efficiency and reduce costs. Prototypes will be built to identify the best amine and catalyst samples. By the end of 2024, the first cell will be built and tested. Next year, a full-scale alkaline amine fuel cell system will be built. It will be tested as a twelve-volt system for current density, lifetime and total costs.
Bismuth Film Electrodes: Characterization and Analytical Application
Authors: Chávez-Vera Sara , García-Bassoco David , Frontana-Uribe Bernardo Antonio
Published: August 2024

Bismuth film electrodes (BiFE) were first introduced more than two decades ago and have been regarded as a posible alternative to toxic traditional mercury electrodes, both for electro-synthesis and electro-analytical endeavors. However, despite all the associated benefits, there hasn’t been a proper characterization reported for this electrodes and their use is still limited.

The present work shows the results of a physicochemical characterization of Bismuth film electrodes, as well as the application of BiFE for the detection and quantification of heavy metals (such as cadmium), which for years have been considered to be important pollutants and are toxic for humans and the environment at large; there for putting at risk the health of all organisms that come into contact with them. The analysis is carried out in a EtOH:H2O mixture at pH 5, simulating the matrix of a traditional mexican alcoholic beverage, Mezcal.

The characterization includes: the calculation of the geometric area as well as the electro-active area of the electrode, the composition of the deposited film and it’s texture, and the electrical properties of the modified electrode.

The analysis is carried out using Anodic Stripping Square Wave Voltammetry (ASSWV), this allows us to make use of the electrode’s ability to form strong interactions with the analyte, in a similar manner to that of mercury drop electrodes; along with the high sensitivity of this technique.
Computational and Experimental Investigations of the Au and NiOOH Interface in the Oxygen Evolution Reaction
Authors: Guan Ginzu , Adelstein Nicole , Qiu Jingjing
Published: August 2024

The transition to renewable energy sources is crucial for combating climate change, and hydrogen (H2) is a promising clean fuel. Electrolysis of water, specifically the oxygen evolution reaction (OER), is a key process for producing H2. Prior experimental results have shown that gold (Au) could improve the apparent activities of the OER electrocatalysts such as nickel hydroxide (Ni(OH)2) in alkaline electrolytes.1-3 However, the detailed interfacial atomic structure and mechanisms of the increased catalytic activity remain poorly understood.

To understand the interfacial effect between Au and Ni(OH)2 in the OER process, our research uses the model system of Au nanoparticles (NPs) and nickel oxyhydroxide (NiOOH), which is the active phase of Ni(OH)2 layers in the OER, to investigate their interfacial interactions with both experimental and computational approaches. We hypothesize that the Au NPs on NiOOH enhances the OER activity by promoting electron transfer at the interface. Our studies involve computational analysis using Density Functional Theory (DFT) calculations to obtain the local density of states (LDOS), which can help us better visualize and compare the local electronic structure of NiOOH in the presence and in the absence of AuNPs. Two architectures of the Au and NiOOH interface will be investigated: Au NPs on a NiOOH film and NiOOH NPs on a Au film.Additionally, Bader analysis is employed to determine the Bader charge, offering a more detailed understanding of how electrons are distributed across the AuNPs/NiOOH interface. Furthermore, the catalytic efficacy of AuNPs on NiOOH is assessed through electrodepositions followed by cyclic voltammetry(CV) measurements. The experimental and computational results will be directly compared, and this research is expected to contribute to the insights of substrate and catalyst interactions for design of more efficient electrocatalysts.

References:

(1) Yeo, B. S.; Bell, A. T. Enhanced Activity of Gold-Supported Cobalt Oxide for the Electrochemical Evolution of Oxygen. J. Am. Chem. Soc.
2011, 133(14), 5587–5593.

(2) Strickler, A. L.; Escudero-Escribano, M.; Jaramillo, T. F. Core-Shell Au@Metal-Oxide Nanoparticle Electrocatalysts for Enhanced Oxygen Evolution. Nano Lett.
2017, 17(10), 6040-6046.

(3) Chakthranont, P.; Kibsgaard, J.; Gallo, A.; Park, J.; Mitani, M.; Sokaras, D.; Kroll, T.; Sinclair, R.; Mogensen, M. B.; Jaramillo, T. F. Effects of Gold Substrates on the Intrinsic and Extrinsic Activity of High-Loading Nickel-Based Oxyhydroxide Oxygen Evolution Catalysts. ACS Catal.
2017, 7(8), 5399– 5409.
A Deep Dive into the Study of Nitrogen-Doped Carbons As Electrocatalysts for the Oxygen Reduction Reaction Via a Design of Experiments Approach
Authors: Mullins C. Buddie , Smith Lettie A , Burrow James N , Eichler John E , Lauro Samantha N , Tang Franklin
Published: August 2024

Porous nitrogen (N)-doped carbons derived from earth-abundant precursors and exhibiting tunable properties hold promise as low-cost, high-performance electrode materials for energy storage and conversion applications. As metal-free electrocatalysts for the oxygen reduction reaction (ORR) at the cathode in hydrogen fuel cells, N-doped carbons have shown selectivity and performance rivaling that of Pt/C. Alternatively, other N-doped carbons have also demonstrated low overpotentials and high selectivity for the 2-electron pathway of the ORR for the production of hydrogen peroxide. The activity and selectivity of these doped carbons are thought to result from their N-content, N-motifs, and/or porosity. However, the extent to which each of these variables impacts electrocatalytic ORR performance and whether there is an interactive effect between N-content, porous structure, etc. remains unclear. Herein, by implementing a design of experiments approach, the synthesis-structure-function relationship for N-doped carbons prepared via molten salt templating was elucidated to reveal how synthetic handles tune material properties which, in turn, determine electrocatalytic performance. Specifically, the wt% of N precursor and the synthesis temperature were found to have the most significant effect on the N-content and N-motif composition of the resulting N-doped carbons. Regarding porosity, larger surface areas and micropore volumes were realized for the carbons prepared with a larger wt% of N precursor. It was found that surface areas upwards of 300 m2/g were required to see any substantial activity (e.g. half-wave potential greater than 0.7 V vs RHE, effective electron transfer number > 3.4). Only after a threshold surface area was achieved were effects from N-content and N-motifs notable on performance and selectivity.
A Tandem Photovoltaic-Electrochemical Photothermal Process for CO2 Conversion to Butene
Authors: Yap Kyra M. K. , Aitbekova Aisulu , Salazar Matthew , Peters Jonas C. , Agapie Theodor , Nielander Adam C. , Atwater Harry A. , Jaramillo Thomas F. , Bell Alexis T.
Published: August 2024

Decarbonizing the chemicals industry requires net carbon negative technologies capable of displacing current greenhouse gas emitting processes. In particular, the generation of valuable monomers, such as butene, are currently produced by significant greenhouse gas emitting processes, including ethylene oligomerization and crude oil refining, which require high temperatures and pressures. Integrated, tandem solar fuels devices for the conversion of CO2 to ethylene, using solar-driven CO2 reduction (CO2R), combined with a photothermal reactor for ethylene oligomerization, offers a potential path to producing clean butene from CO2, using solar energy as the only driving force. A key challenge for the successful operation of a tandem photo-driven electrochemical-photothermal system is the co-design of the two processes, which are typically optimized under different operating conditions. Specifically, photo-driven electrochemical CO2R (pCO2R) reactors operate under ambient temperature and pressure conditions while thermally-driven ethylene oligomerization reactors prefer elevated temperatures (80-140 °C) and pressures (30-150 atm) to promote high activity as well as pure ethylene in the inlet stream. Operation of the tandem process under solar-driven conditions imposes additional constraints on the maximum power output of the pCO2R reactor and the maximum temperature which can be obtained in the photothermal reactor. Herein, we present an unassisted solar-driven tandem system coupling pCO2R with photothermal ethylene oligomerization for the conversion of CO2 to butene in a single pass. This work presents a critical advancement in the development of solar fuels technologies for larger hydrocarbon generation and identifies the co-design principles which must be considered for implementation of tandem, solar-driven electrochemical-thermal processes.
Incorporating Electrochemistry and Battery Technology in an Undergraduate Materials Science Course
Authors: Saqib Najmus
Published: August 2024

Electrochemical devices and systems are ubiquitous in many engineering disciplines, yet basic electrochemistry principles are rarely covered in the typical undergraduate engineering curriculum. This presents a barrier for young engineers aspiring to make contributions to this fast-growing field, as well as primary investigators in electrochemical engineering at undergraduate-only institutions. In the field of mechanical engineering, one of the oldest and arguably the broadest engineering disciplines, energy storage and conversion are covered in depth at the undergraduate level. However, electrochemical energy storage and conversion are only briefly glanced, if at all. As part of curriculum development in a new undergraduate mechanical engineering program, electrochemistry fundamentals, with a focus on applications to battery technology, were deliberately incorporated into a second-year materials science course.

Undergraduate materials science courses typically focus on general process-structure-property relationships of different engineering materials, and this course is no different. Instead of covering only traditional materials, significant time is also devoted to battery materials, which are very relevant and poised for exponential growth in this era of electric vehicles and renewable energy storage. The course includes instruction on basic electrochemical principles, a survey of functional materials used in common electrochemical devices and their properties, as well as a short lab project where students are guided through the steps of constructing a simple coin-cell lithium-ion battery, arguably the most dominant of all battery chemistries. Classroom discussion also includes the environmental impacts of sourcing raw battery materials and end-of-life disposal practices, which, given current projections, will lead to a substantial sustainability problem as the battery market grows with electric vehicle uptake. Emerging battery technologies that seek to address the challenges of the current generation of batteries are also introduced. Students are also asked to give a short presentation after researching additional topics in the field that are of interest to them. Overall, the course aims to help modernize the undergraduate mechanical engineering curriculum by incorporating electrochemistry principles and battery technology into a core course.
A Green Slurry Electrolysis to Recover Valuable Metals from Waste Printed Circuit Board (WPCB) in Recyclable pH-Neutral Ethylene Glycol
Authors: Lam Jason Chun-Ho
Published: August 2024

The continuous growth of e-waste necessitates an efficient method to recover their metal contents to improve their recycling rate. The successful recovery of the metallic component from Waste Electrical and Electronic Equipment (WEEE) can generate great economic benefits to incentivize the industrial recycling effort. In this study, we report the use of slurry electrolysis (SE) in pH-neutral ethylene glycol (EG) electrolyte to extract and recover the metallic component from waste printed circuit broad (WPCB) powder. The system operates at room temperature and atmospheric pressure, and the electrolyte can be recycled multiple times with no signs of chemical degradation. The EG electrolyte system can oxidize the metallic component without triggering anodic gas evolution, which allowed us to incorporate a reticulated vitreous carbon (RVC) foam anode to maximize the capture and oxidation of the metal content. The system demonstrated up to 99.1% Faraday efficiency for the cathodic metal deposition and could recover Cu from the WPCB powder in a selective manner of 59.7% in the presence of 12 other metals. The SE reaction system was also scalable and displayed no compromises on the Cu recovery selectivity. With the ability to leach and recover metallic content from WPCB in a mild and chemically benign condition, the SE system displayed much promise to be adapted for industrial-scale metal recovery from WPCB.

Reference

Liu, K., Lam, JCH. et al. "A green slurry electrolysis to recover valuable metals from waste printed circuit board (WPCB) in recyclable pH-neutral ethylene glycol." J. Hazard. Mater.
2022433: 128702.

Liu, K., Lam, JCH. et al. "Teaching Electrometallurgical Recycling of Metals from Waste Printed Circuit Boards via Slurry Electrolysis Using Benign Chemicals." J. Chem. Educ.
2023 100(2): 782-790.

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Repair and Reuse of Spent Lithium Battery Electrode Materials
Authors: Zhou Guangmin
Published: August 2024

With the popularity of new energy vehicles and various electronic devices, the use of lithium-ion batteries (LIBs) has shown explosive growth, which has resulted in a large number of spent LIBs. Spent LIBs contain a large amount of metal resources, and improper disposal will not only cause waste of resources, but also have potential environmental risks. The existing commercial recycling methods are mainly pyrometallurgy and hydrometallurgy recycling methods, both of which require re-extraction from the electrode material after destroying them to the atomic level for the preparation of new electrode materials, which is a long process with high cost, and involves the application of extreme conditions such as high temperature and strong acid, with inferior economic and environmental benefits. It is a major challenge in the field of battery recycling to develop innovative and clean recycling methods, to simplify the recycling process and to develop ways to reuse the recovered products. In view of the challenge of existing recycling methods, the reporters proposed the idea of direct recycling of electrode materials at the molecular scale, and designed innovative recycling methods such as direct repair of degraded lithium cobalt oxides with deep eutectic solvent (DES), repair of Ni-Mn-Co ternary (NCM) cathode with high failure degree by low temperature molten salt, and thermal regeneration of degraded lithium iron phosphate (LFP) with multifunctional solvent; and closed-loop design of the direct recycling process. In addition, we propose a high-value utilization path for the conversion of degraded electrode materials to high-performance electrode materials and nano-catalysts. It greatly simplifies the recycling process, avoids the use of extreme conditions, and provides a new technical system and theoretical guidance for battery recycling research and industry.
(Invited) Recycling of Perfluorosulfonic-Acid Polymers, into Commercial Viable Second-Use Applications
Authors: Grot Stephen Andreas
Published: August 2024

This presentation will describe our efforts to commercialize our technology to re-deploy spent perfluorosulfonic acid (PFSA) polymer materials from end-of-life Hydrogen Economy energy conversion systems into second-use applications.

The challenge in any recycling effort for the PFSA materials is to find a marketable application for the recovered polymer. This is in stark contrast to the situation for the precious group metals; where any recycling/recovery effort for PGM materials can be quickly and easily brought back to the market and converted to cash. This is why so much of the current end-of-life PGM bearing scrap is currently incinerated in order to recover the PGM value only. We will report on the development of several applications from polymer that we have purified and recovered from end-of-life Hydrogen Economy systems.