Diffusiophoresis-enhanced particle deposition for additive manufacturing
The ability to govern particle assembly in an evaporative-driven additive manufacturing (AM) can realize multi-scale features fundamental to creating printed electronics. However, existing techniques remain challenging and often require templates or contaminating solutes. We explore the control of particle deposition in 3D-printed colloids by diffusiophoresis, a previously unexplored mechanism in multi-scale AM. Diffusiophoresis can introduce spontaneous phoretic particle motion by establishing local solute concentration gradients. We show that diffusiophoresis can play a dominant role in complex evaporative-driven particle assembly, enabling a fundamentally new and versatile control of particle deposition in a multi-scale AM process.
Material extrusion additive manufacturing of dense pastes consisting of macroscopic particles
Additive manufacturing of dense pastes, those with greater than 50 vol% particles, via material extrusion direct ink write is a promising method to produce customized structures for high-performance materials, such as energetic materials and pharmaceuticals, as well as to enable the use of waste or other locally available particles. However, the high volume fraction and the large sizes of the particles for these applications lead to significant challenges in developing inks and processing methods to prepare quality parts. In this prospective, we analyze challenges in managing particle characteristics, stabilizing the suspensions, mixing the particles and binder, and 3D printing the pastes.
Diffusive drug delivery in the brain extracellular space from a cellular scale microtube
The effectiveness of state-of-the-art systemic treatments for neurological disorders is hampered not only by the difficulty in crossing the blood brain barrier but also off-target drug interactions. In this study, a delivery method is simulated for a novel U-shaped microtube locally infusing drugs directly into the extracellular space of the brain and relying on diffusion as a transport mechanism. The influence of flow rate, drug properties and device geometry are investigated. It is anticipated that these findings will accelerate progress on both developmental and applied drug delivery and materials research.
Quantitative multi-image analysis in metals research
Quantitative multi-image analysis (QMA) is the systematic extraction of new information and insight through the simultaneous analysis of multiple, related images. We present examples illustrating the potential for QMA to advance materials research in multi-image characterization, automatic feature identification, and discovery of novel processing-structure-property relationships. We conclude by discussing opportunities and challenges for continued advancement of QMA, including instrumentation development, uncertainty quantification, and automatic parsing of literature data.
Statistical methods for design and testing of 3D-printed polymers
Different statistical methods are used in various fields to qualify processes and products, especially in emerging technologies like Additive Manufacturing (AM) or 3D printing. Since several statistical methods are being employed to ensure quality production of the 3D-printed parts, an overview of these methods used in 3D printing for different purposes is presented in this paper. The advantages and challenges, to understanding the importance it brings for design and testing optimization of 3D-printed parts are also discussed. The application of different metrology methods is also summarized to guide future researchers in producing dimensionally-accurate and good-quality 3D-printed parts. This review paper shows that the Taguchi Methodology is the commonly-used statistical tool in optimizing mechanical properties of the 3D-printed parts, followed by Weibull Analysis and Factorial Design. In addition, key areas such as Artificial Intelligence (AI), Machine Learning (ML), Finite Element Analysis (FEA), and Simulation require more research for improved 3D-printed part qualities for specific purposes. Future perspectives are also discussed, including other methods that can help further improve the overall quality of the 3D printing process from designing to manufacturing.
Investigating the beneficial effects of a WO seed layer on the mechanical and photoelectrochemical stability of WO|BiVO|NiFeOOH photoanodes under operational conditions
Scalable and durable photoelectrodes are essential for technological breakthroughs in photoelectrochemical systems, yet the fragility of nanostructured photocatalyst materials in industrially relevant operating conditions is rarely explored. Herein, we advance understanding of the importance of morphology and temperature on stability and performance of nanostructured WO|BiVO|NiFeOOH photoanodes. The integration of a planar WO seed layer beneath nanostructured WO, improved mechanical stability at 40°C with flowing electrolyte approximately twofold compared with materials where a seed layer was not integrated. This work provides a pathway through which robust photoelectrode systems can be engineered to enable the advancement of up-scaled photoelectrochemical water splitting.
Co-delivery of genes can be confounded by bicistronic vector design
Maximizing the efficiency of nanocarrier-mediated co-delivery of genes for co-expression in the same cell is critical for many applications. Strategies to maximize co-delivery of nucleic acids (NA) focused largely on carrier systems, with little attention towards payload composition itself. Here, we investigated the effects of different payload designs: co-delivery of two individual "monocistronic" NAs versus a single bicistronic NA comprising two genes separated by a 2A self-cleavage site. Unexpectedly, co-delivery via the monocistronic design resulted in a higher percentage of co-expressing cells, while predictive co-expression via the bicistronic design remained elusive. Our results will aid the application-dependent selection of the optimal methodology for co-delivery of genes.
Nanomaterials in diagnostics, imaging and delivery: Applications from COVID-19 to cancer
In the past two decades, the emergence of nanomaterials for biomedical applications has shown tremendous promise for changing the paradigm of all aspects of disease management. Nanomaterials are particularly attractive for being a modularly tunable system; with the ability to add functionality for early diagnostics, drug delivery, therapy, treatment and monitoring of patient response. In this review, a survey of the landscape of different classes of nanomaterials being developed for applications in diagnostics and imaging, as well as for the delivery of prophylactic vaccines and therapeutics such as small molecules and biologic drugs is undertaken; with a particular focus on COVID-19 diagnostics and vaccination. Work involving bio-templated nanomaterials for high-resolution imaging applications for early cancer detection, as well as for optimal cancer treatment efficacy, is discussed. The main challenges which need to be overcome from the standpoint of effective delivery and mitigating toxicity concerns are investigated. Subsequently, a section is included with resources for researchers and practitioners in nanomedicine, to help tailor their designs and formulations from a clinical perspective. Finally, three key areas for researchers to focus on are highlighted; to accelerate the development and clinical translation of these nanomaterials, thereby unleashing the true potential of nanomedicine in healthcare.
Materials-driven strategies in bacterial engineering
This perspective article focuses on the innovative field of materials-based bacterial engineering, highlighting interdisciplinary research that employs material science to study, augment, and exploit the attributes of living bacteria. By utilizing exogenous abiotic material interfaces, researchers can engineer bacteria to perform new functions, such as enhanced bioelectric capabilities and improved photosynthetic efficiency. Additionally, materials can modulate bacterial communities and transform bacteria into biohybrid microrobots, offering promising solutions for sustainable energy production, environmental remediation, and medical applications. Finally, the perspective discusses a general paradigm for engineering bacteria through the materials-driven modulation of their transmembrane potential. This parameter regulates their ion channel activity and ultimately their bioenergetics, suggesting that controlling it could allow scientists to hack the bioelectric language bacteria use for communication, task execution, and environmental response.
Impact of coverage and guest residue on polyproline II helix peptide antifouling
Polyproline II (PPII) peptide sequences are recognized as promising biomaterials because of their attractive antifouling properties. However, the mechanisms behind their antifouling behavior have not been fully characterized. In this work we show that PPII peptide coverage, controlled by adsorption time, significantly reduces the fouling of bovine serum albumin (BSA, a model foulant). In addition, guest residues introduced into the PPII sequence are shown to significantly impact BSA adsorption as well as human mesenchymal stem cell (hMSC) spreading. This research will help guide future PPII peptide designs for incorporation into novel biomaterials.
Progress of emerging non-volatile memory technologies in industry
This prospective and performance summary provides a view on the state of the art of emerging non-volatile memory (eNVM) in the semiconductor industry. The overarching aim is to inform academic researchers of the status of these technologies in industry, so as to help direct the right academic research questions for future materials and device development. eNVM already have a strong foothold in the semiconductor industry with the main target of replacing embedded flash memory, and soon possibly DRAM and SRAM, i.e. replacing conventional memory. Magnetic and resistive memory are the current frontrunners among eNVM for embedded flash replacement and they are very advanced in this, which poses high demands on future academic research for eNVM for this purpose. Phase-change and ferroelectric memory are less available as commercially available products. The use of eNVM for new forms of artificial intelligence hardware is a much more open field for future academic research.
Materials approaches for next-generation encapsulated cell therapies
Transplanted cells can act as living drug factories capable of secreting therapeutic proteins , with applications in the treatment of Type 1 diabetes (T1D), blood borne disease, vision disorders, and degenerative neural disease, potentially representing functional cures for chronic conditions. However, attack from the host immune system represents a major challenge, requiring chronic immunosuppression to enable long-lived cell transplantation . Encapsulating cells in engineered biomaterials capable of excluding components of the host immune system while allowing for the transport of therapeutic proteins, oxygen, nutrients, metabolites, and waste products represents a potential solution. However, the foreign-body response can lead to isolation from native vasculature and hypoxia leading to cell death. In this prospective article, we highlight materials-based solutions to three important challenges in the field: (i) improving biocompatibility and reducing fibrosis; (ii) enhancing transport of secreted protein drugs and key nutrients and oxygen engineered, semipermeable membranes; and (iii) improving oxygenation. These efforts draw on several disciplines in materials' research, including polymer science, surfaces, membranes, biomaterials' microfabrication, and flexible electronics. If successful, these efforts could lead to new therapies for chronic disease and are a rich space for both fundamental materials' discovery and applied translational science.
Optoionics: New opportunity for ionic conduction-based radiation detection
Optoionics, involving light-modulated ionic transport in ionic solids, parallels optoelectronics in semiconductors and offers novel device design opportunities across various fields. Among these opportunities, grain boundary phenomena related to radiation-induced electron/hole pair generation and charge trapping at the boundaries causing a modulation in ionic current could enable fast, sensitive, and reversible radiation detectors. The robustness of ionic solids in chemical, structural, and thermal aspects in turn makes them scalable and robust alternatives to traditional semiconductor detectors. This article explores the theoretical underpinnings, experimental breakthroughs, and design considerations needed to optimize such optoionic devices.
Co-stimulation with equibiaxial strain and pre-osteoblast co-culture differentiates monocytes in a bone model
Bone remodeling and immune function are dynamically regulated through cell-cell and cell-matrix interactions by stem and mature cell populations. We investigated the hypothesis that monocytes and pre-osteoblasts respond to cyclic tensile stress and paracrine interactions by differentiating into macrophage-like and osteoblast-like cells. 20% cyclic equibiaxial strain was applied to monocytic U937 and pre-osteoblastic ST2 cells for 72 h. Increased levels of CD11B, CD14, IL-6, and IL-8 in U937 indicated monocytic differentiation. Increased ALP expression and calcium deposition in ST2 indicated differentiation towards osteoblastic lineage. Overall, application of cyclic strain and pre-osteoblastic co-culture induced differentiation in this cyclically strained bone model.
Detection of SARS-COV-2 by functionally imprinted micelles
The near real-time detection of airborne particles-of-interest is needed for avoiding current/future threats. The incorporation of imprinted particles into a micelle-based electrochemical cell produced a signal when brought into contact with particle analytes (such as SARS-COV-2), previously imprinted onto the structure. Nanoamp scales of signals were generated from what may've been individual virus-micelle interactions. The system showed selectivity when tested against similar size and morphology particles. The technology was compatible with airborne aerosol sampling techniques. Overall, the application of imprinted micelle technology could provide near real-time detection methods to a host of possible analytes of interest in the field.
Copper-carbon hybrid nanoparticles as antimicrobial additives
Millions of cases of hospital-acquired infections occur every year involving difficult to treat bacterial and fungal agents. In an effort to improve patient outcomes and provide better infection control, antimicrobial coatings are ideal to apply in clinical settings in addition to aseptic practices. Most efforts involving effective antimicrobial surface technologies are limited by toxicity of exposure due to the diffusion. Therefore, surface-immobilized antimicrobial agents are an ideal solution to infection control. Presented herein is a method of producing carbon-coated copper/copper oxide nanoparticles. Our findings demonstrate the potential for these particles to serve as antimicrobial additives.
Simple dynamic cell culture system reduces recording noise in microelectrode array recordings
Microelectrode arrays (MEAs) have applications in drug discovery, toxicology, and basic research. They measure the electrophysiological response of tissue cultures to quantify changes upon exposure to biochemical stimuli. Unfortunately, manual addition of chemicals introduces significant noise in the recordings. Here, we report a simple-to-fabricate fluidic system that addresses this issue. We show that cell cultures can be successfully established in the fluidic compartment under continuous flow conditions and that the addition of chemicals introduces minimal noise in the recordings. This dynamic cell culture system represents an improvement over traditional tissue culture wells used in MEAs, facilitating electrophysiology measurements.
Polymer-BiI composites for high-performance, room-temperature, direct X-ray detectors
Low-energy X-rays have a predominant role in medical diagnostic applications, grown tremendously during recent Covid-19 pandemic times. Synthesis of stable, PMMA/polystyrene-BiI composites has been done through a facile, low-cost, dry-tumble mixing technique for direct X-ray detector applications. Comparative analysis of structural, optical, and photocurrent responses upon irradiation with low-energy X-rays (30 and 60 kV) ensue that PS-BiI demonstrates high SNR 3300, sensitivity 189 µC Gy cm and fast response time 30 ms, at dose rate 1.68 mGy s, affirming the composite to be prospective candidate for low-energy, room-temperature, direct X-ray detectors under low bias conditions.
A review of materials used in tomographic volumetric additive manufacturing
Volumetric additive manufacturing is a novel fabrication method allowing rapid, freeform, layer-less 3D printing. Analogous to computer tomography (CT), the method projects dynamic light patterns into a rotating vat of photosensitive resin. These light patterns build up a three-dimensional energy dose within the photosensitive resin, solidifying the volume of the desired object within seconds. Departing from established sequential fabrication methods like stereolithography or digital light printing, volumetric additive manufacturing offers new opportunities for the materials that can be used for printing. These include viscous acrylates and elastomers, epoxies (and orthogonal epoxy-acrylate formulations with spatially controlled stiffness) formulations, tunable stiffness thiol-enes and shape memory foams, polymer derived ceramics, silica-nanocomposite based glass, and gelatin-based hydrogels for cell-laden biofabrication. Here we review these materials, highlight the challenges to adapt them to volumetric additive manufacturing, and discuss the perspectives they present.
Rapid testing for coronavirus disease 2019 (COVID-19)
Rapid testing, generally refers to the paper-based diagnostic platform known as "lateral flow assay" (LFA), has emerged as a critical asset to the containment of coronavirus disease 2019 (COVID-19) around the world. LFA technology stands out amongst peer platforms due to its cost-effective design, user-friendly interface, and low sample-to-readout times. This article aims to introduce its design, use, and practicality for the purpose of diagnosing SARS-CoV-2 infection. A connection is made from the normal COVID-19 immune response to the design and efficacy of rapid testing. Interference in test results is a challenge shared by most diagnostic platforms and can be rooted in various underlying issues. The current knowledge and situation about interference in rapid COVID-19 tests due to variant strains as well as vaccination are discussed. The cost and societal impact are reviewed as they play important roles in determining how to properly implement public testing practices. Perspectives on improving the performance, especially detection sensitivity, of LFA for COVID-19 are provided.
Additive manufacturing and rheological characterization of ceramic matrix composite inks with high fiber volume loadings
Additive manufacturing of fiber-filled ceramic matrix composites (CMCs) can be used to tune local properties controlled fiber orientation. Increasing the loading of fibers in additively manufactured CMCs is needed to improve the fracture toughness, yet printing CMCs with high fiber loadings (> 20 vol%) remains challenging. In this work, the combination of viscous silicon oxycarbide preceramic resins, short carbon fibers (50 µm × 7 µm), and Vibration-Assisted Printing enable printing of a mixture with 39.4-vol.% carbon fiber (total loading of 43.3 vol%) with omnidirectional fibers within the bead.
