Assembly Applications Research Articles

Augmented Reality for Quality Inspection, Assembly and Remote Assistance in Manufacturing

In recent years, the manufacturing industry has witnessed the utilization of Augmented Reality (AR) technologies in their daily operations. This paper takes a deep dive into the applications of AR in the manufacturing industry, specifically focusing on quality inspection, assembly, and remote assistance. This research offers valuable insights into the technical architectures using custom and commercial software, as well as the Proof of Concept (PoC) applications for Hand-Held Device (HHD) and Head-Mounted Device (HMD). The custom application for an HHD combines the state-of-the-art You Only Look Once (YOLO) object detection algorithm to enable AR for quality inspection. We used commercial software from Pocket virtuality® to develop assembly and remote assistance applications for an HMD. An applied research approach was adopted, incorporating the collection of both quantitative and qualitative data to assess the various application scenarios. Among the key findings, it is evident that the functionality of the custom-developed app for quality inspection is contingent upon the operating system, software libraries available on the HHD, and the chosen version of the YOLO detection model. Furthermore, through quantitative and qualitative analysis, it becomes apparent that the software and hardware components of the HMD require significant improvements. These findings offer a high potential for improvement and emphasize the need for further research in the field. Moreover, this research emphasizes the fact that AR has the potential to make a huge impact on the manufacturing industry.

An Effective Virtual Reality Paradigm for Robotic Assembly in First-Year Engineering Curriculum

An effective Augmented Reality and Virtual Reality paradigm is proposed to facilitate introductory robotics course in the first-year engineering curriculum. The AR/VR Application utilization and its impact on the students' learning with respect to robotic assembly and robotic application programming is emphasized in this article. The paper delves into a comprehensive review of the related works presented in the literature. The requirements for the physical assembly and virtual assembly of movable robots are meticulously highlighted. To facilitate course learning a robotic workshop involving steps introduction to robotics, and practical experience on the robot is conducted. The delivery of the course content is made much more effective by inculcating the Virtual experience of the Robotic assembly process. The virtual robotic assembly and manual physical robotic assembly process processes have their own uniqueness and importance and it is left to the students to pick them on a priority basis. Finally, the effectiveness of the proposed course is determined by conducting an online quiz, collecting student feedback, tabulating and analyzing the results.The results demonstrate the effectiveness of the proposed method in creating interest in robotics and related courses among first-year engineering students. Keywords— Augmented Reality(AR), Virtual Reality(VR), Build Your Own Robot(BYOR), Robotic assembly.

Recent advances in carrier-free natural small molecule self-assembly for drug delivery.

Natural small-molecule drugs have been used for thousands of years for the prevention and treatment of human diseases. Most of the natural products available on the market have been modified into various polymer materials for improving the solubility, stability, and targeted delivery of drugs. However, these nanomedicines formed based on polymer carriers would produce severe problems such as systemic toxicity and kidney metabolic stress. In contrast, the carrier-free nanomedicines formed by their self-assembly in water have inherent advantages such as low toxicity, good biocompatibility, and biodegradability. This review summarizes the assembly process and application of natural small-molecule products, which are mainly driven by multiple non-covalent interactions, and includes single-molecule assembly, bimolecular assembly, drug-modified assembly, and organogels. Meanwhile, the molecular mechanism involved in different self-assembly processes is also discussed. Self-assembly simulation and structural modification of natural small-molecule products or traditional Chinese medicine molecules using molecular dynamics simulation and computer-assisted methods are proposed, which will lead to the discovery of more carrier-free nanomedicine drug delivery systems. Overall, this review provides an important understanding and strategy to study single-molecule and multi-molecule carrier-free nanomedicines.

Electrochemical Characterization of Artificial Solid Electrolyte Interphase Developed on Graphite Via ALD

During formation of Li-ion batteries, a ‘natural’ solid electrolyte interphase (SEI) is formed at the anode side by decomposition products of the electrolyte. The properties of the SEI are extremely decisive for the overall battery properties, such as rate capability and cycling stability. However, the SEI formation consumes Li, leading to so called ‘formation losses’ that can make up to 15% of the theoretical energy density of the battery. Several approaches have been presented to overcome formation losses while preserving excellent overall battery properties. Particularly, electrochemical prelithiation and the application of artificial SEIs prior cell assembly are considered to effectively reduced formation losses while improving the interfacial charge transfer properties and increasing cycling stability.Herein, the authors present an innovative approach of applying a multifunctional artificial SEI on anode material powders via consecutive atomic layer deposition (ALD) cycles. As a model system, graphite powder has been chosen to be modified and characterized.The resulting electrodes show substantially improved electrochemical performance in half cells and full cells, regarding initial capacity loss, CE and cycling stability. Furthermore, model electrodes consisting of a single layer of graphite particles were manufactured, which exclude the effects of a typical composite electrode and therefore reveal the intrinsic properties of the active material. Using this approach, the interfacial kinetics and the rate capability are investigated comparatively between pristine and ALD coated electrodes, revealing the impact of the artificial SEI on the materials level.

Immunotherapy against tau pathology in mouse models requires cytosolic Fc receptor TRIM21

AbstractBackgroundThe passive transfer of monoclonal antibodies reduces tau pathology in mouse models and is under evaluation as a potential immunotherapeutic strategy against Alzheimer’s disease and other tauopathies. The mechanisms that drive therapeutic protection of anti‐tau antibodies are not well understood.MethodP301S tau transgenic animals were treated with antibodies against pS422 and analysed for tau pathology by biochemical fractionation. Organotypic hippocampal slice cultures were used as a model of tau seeding and neutralisation. AAV serotypes were used to deliver tau‐selective degraders.ResultGenetic deletion of the cytosolic antibody receptor and E3 ubiquitin ligase TRIM21 rendered tau immunotherapy ineffective in animal models. In organotypic slices, expression of TRIM21 was essential for protection against seeded aggregation of tau. Cytosolic antibody‐tau complexes were visible inside neurons in complex with TRIM21 shortly after application of tau assemblies and antibodies to the cell exterior. Nanobody‐based degraders were developed using TRIM21 and found to protect against tau pathology.ConclusionAnti‐tau antibodies can engage extracellular tau seeds and enter neurons as a complex. Following cytosolic entry, TRIM21 engages the antibodies and mediates neutralisation of tau seeding activity. The results reveal a mechanism that can be optimised for future immunotherapeutics. In this direction, AAV‐delivered degraders reveal a route by which tau aggregates may be selectively removed from the brain.

On process capability of single screw extruder for fabricating PVDF composite matrix

In this study, a single screw extruder (SSE) was used to fabricate the poly (vinylidene fluoride) (PVDF) matrix inform of filament forthe material extrusion process in line with sustainable development goal (SDG) (with a special target on the industry, innovation, and infrastructure). For industrial use, the fabricated filament must be statistically controlled from a dimensional deviation viewpoint, so an effort has been made to ascertain the process capability of SSE based on the diameter of the filament. The study's findings indicate that the fabricated PVDF composite filaments are statistically controlled, as the process capability indices (Cp and Cpk) are > 1. The best setting for the SSE (for the minimum deviation) in the case of compositions A/B and D are a screw temperature of 220 °C and a screw speed of 7 rpm. For composition C the screw temperature was 230 °C and the screw speed of 7 rpm. The controlled dimensional deviations are also presented as international tolerance (IT) grades for assembly applications.

On dimensional stability of 3D printed functional prototypes for assembly applications

In this study, functional prototypes for bio-medical applications were 3D printed by using fused deposition modeling (FDM). For the fabrication of the parts, acrylonitrile butadiene styrene (ABS) material was used in this study. For accessing the dimensional stability of a fabricated prototype a hernia mesh implant was selected as a benchmark, in assembly. The dimensional stability was accessed in the form of an international tolerance grade (IT Grade) based on various dimensions of the components. The study indicates that the fabricated ABS components are under controlled dimensional deviations according to the IT grades for assembly applications. As regards tolerances, the IT grades varied from IT to 8–10 in most of the cases, which justifies the use of these components for assembly in batch production.

Spatiotemporal Control over Polynucleotide Brush Growth on DNA Origami Nanostructures

AbstractDNA nanotechnology provides an approach to create precise, tunable, and biocompatible nanostructures for biomedical applications. However, the stability of these structures is severely compromised in biological milieu due to their fast degradation by nucleases. Recently, we showed how enzymatic polymerization could be harnessed to grow polynucleotide brushes of tunable length and location on the surface of DNA origami nanostructures, which greatly enhances their nuclease stability. Here, we report on strategies that allow for both spatial and temporal control over polymerization through activatable initiation, cleavage, and regeneration of polynucleotide brushes using restriction enzymes. The ability to site‐specifically decorate DNA origami nanostructures with polynucleotide brushes in a spatiotemporally controlled way provides access to “smart” functionalized DNA architectures with potential applications in drug delivery and supramolecular assembly.

Spatiotemporal Control over Polynucleotide Brush Growth on DNA Origami Nanostructures.

DNA nanotechnology provides an approach to create precise, tunable, and biocompatible nanostructures for biomedical applications. However, the stability of these structures is severely compromised in biological milieu due to their fast degradation by nucleases. Recently, we showed how enzymatic polymerization could be harnessed to grow polynucleotide brushes of tunable length and location on the surface of DNA origami nanostructures, which greatly enhances their nuclease stability. Here, we report on strategies that allow for both spatial and temporal control over polymerization through activatable initiation, cleavage, and regeneration of polynucleotide brushes using restriction enzymes. The ability to site-specifically decorate DNA origami nanostructures with polynucleotide brushes in a spatiotemporally controlled way provides access to "smart" functionalized DNA architectures with potential applications in drug delivery and supramolecular assembly.

Advance Progress in Assembly Mechanisms of Carrier-Free Nanodrugs for Cancer Treatment.

Nanocarriers have been widely studied and applied in the field of cancer treatment. However, conventional nanocarriers still suffer from complicated preparation processes, low drug loading, and potential toxicity of carriers themselves. To tackle the hindrance, carrier-free nanodrugs with biological activity have received increasing attention in cancer therapy. Extensive efforts have been made to exploit new self-assembly methods and mechanisms to expand the scope of carrier-free nanodrugs with enhanced therapeutic performance. In this review, we summarize the advanced progress and applications of carrier-free nanodrugs based on different types of assembly mechanisms and strategies, which involved noncovalent interactions, a combination of covalent bonds and noncovalent interactions, and metal ions-coordinated self-assembly. These carrier-free nanodrugs are introduced in detail according to their assembly and antitumor applications. Finally, the prospects and existing challenges of carrier-free nanodrugs in future development and clinical application are discussed. We hope that this comprehensive review will provide new insights into the rational design of more effective carrier-free nanodrug systems and advancing clinical cancer and other diseases (e.g., bacterial infections) infection treatment.

“Live” Nanomaterials Process Biomimetic Recognition and Assembly In Vivo

The biomimetic strategy has been widely used in multiple fields, and provides huge convenience to human life. For biomedical application in vivo, the importance of biomimetic materials lies on mimicking the natural process/behavior as well as mimicking the structure/ingredient. Herein, recent advances of materials processing biomimetic recognition and assembly behavior for in vivo applications, including the natural source materials and artificial materials, are summarized. The biological processes are divided as recognition and assembly as well as recognition and self‐amplifying assembly. Finally, to conclude, the application of recognition and assembly process‐biomimetic materials in vivo in the future is discussed.

Application of membrane electrode assembly for water hydrogen isotope exchange

Hydrogen isotope separation will be important for future hydrogen energy applications. The materials used in polymer electrolyte fuel cells (PEFCs), such as the hydrophobic support and Pt catalyst, are essentially the same to those used in the conventional isotope-separation method of water hydrogen chemical exchange. Hereby, deuterium (D) separation was performed with a PEFC. The separation was improved with increasing the water vapor and temperature. D was enriched into the dew water in the cell. The quantities of D conversion from the gas through the vapor to the dew water was measured. The conversion values were less than the simulated ones. This was attributed to the vapor pressure drop and the wetted catalyst surface by the water condensation.

Recent advancements in bionanomaterial applications of peptide nucleic acid assemblies.

Peptide nucleic acid (PNA) is a unique combination of peptides and nucleic acids. PNA can exhibit hydrogen bonding interactions with complementary nucleobases like DNA/RNA. Also, its polyamide backbone allows easy incorporation of biomolecules like peptides and proteins to build hybrid molecular constructs. Because of chimeric structural properties, PNA has lots of potential to build diverse nanostructures. However, progress in the PNA material field is still immature compared with its massive applications in antisense oligonucleotide research. Examples of well-defined molecular assemblies have been reported with PNA amphiphiles, self-assembling guanine-PNA monomers/dimers, and PNA-decorated nucleic acids/ polymers/ peptides. All these works indicate the great potential of PNA to be used as bionanomaterials. The review summarizes the recent reports on PNA-based nanostructures and their versatile applications. Additionally, this review shares a perspective to promote a better understanding of controlling molecular assembly by the systematic structural modifications of PNA monomers.

Programming assembly of biomimetic exosomes: An emerging theranostic nanomedicine platform.

Exosomes have emerged as a promising cell-free therapeutic approach. However, challenges in large-scale production, quality control, and heterogeneity must be overcome before they can be used clinically. Biomimetic exosomes containing key components of natural exosomes have been assembled through extrusion, artificial synthesis, and liposome fusion to address these limitations. These exosome-mimetics (EMs) possess similar morphology and function but provide higher yields, faster large-scale production, and similar size compared to conventional exosomes. This article provides an overview of the chemical and biological properties of various synthetic exosome systems, including nanovesicles (NVs), EMs, and hybrid exosomes. We highlight recent advances in the production and applications of nanobiotechnology and discuss the advantages, limitations, and potential clinical applications of programming assembly of exosome mimetics.

Site-specific crosslinking and assembly of tetrameric β-glucuronidase improve glycyrrhizin hydrolysis.

In this study, eight nonconserved residues with exposed surfaces and flexible conformations of the homotetrameric PGUS (β-glucuronidase from Aspergillus oryzae Li-3) were identified. Single-point mutation into cysteine enabled the thiol-maleimide reaction and site-specific protein assembly using a two-arm polyethylene glycol (PEG)-maleimide crosslinker (Mal2 ). The Mal2 (1k) (with 1 kDa PEG spacer)-crosslinked PGUS assemblies showed low crosslinking efficiency and unimproved thermostability except for G194C-Mal2 (1k). To improve the crosslinking efficiency, a lengthened crosslinker Mal2 (2k) (with 2 kDa PEG spacer) was used to produce PGUS assembly and a highly improved thermostability was achieved with a half-life of 47.2-169.2 min at 70°C, which is 1.04-3.74 times that of wild type PGUS. It is found that the thermostability of PGUS assembly was closely associated with the formation of inter-tetramer assembly and intratetramer crosslinking, rather than the PEGylation of the enzyme. Therefore, the four-arm PEG-maleimide crosslinker Mal4 (2k) (with 2 kDa PEG spacer) was employed to simultaneously increase the inter-tetramer assembly and intratetramer crosslinking, and the resulting PGUS assemblies showed further improved thermostabilities compared with Mal2 (2k)-crosslinked assemblies. Finally, the application of PGUS assemblies with significantly improved thermostability to the bioconversion of GL proved that the PGUS assembly is a strong catalyst for glycyrrhizin (GL) hydrolysis in industrial applications.

Learning-based acoustic displacement field modeling and micro-particle control

Acoustic manipulation has emerged as a promising microtarget control method with potential applications in microchip assembly, noncontact control of chemical materials, and cell control. However, the precision of acoustic micro-/nano-manipulation is constrained by the ambiguity of the acoustic displacement field. The nonlinear properties of displacement fields cannot be appropriately simulated using conventional mathematical fitting techniques. In this study, considering the complexity of particle motion on a thin plate driven by acoustic waves, the original displacement dataset was collected based on an experimental platform and was then trained using a neural network to model the displacement of unknown points on the plate. The corresponding cost functions were designed based on a manipulation task and particle number to determine the frequency sequence and achieve motion control of micro/nano targets by selecting the driving frequency with the lowest cost during the controlling process. Based on the above predictions and control effects, the acoustic manipulation platform constructed in this study could be used to manipulate the linear motion of a single particle and control multiple particle encounters as well as to manipulate the complex trajectory “NK”. This work opens up an accessible path for an acoustic displacement field and enables achievable microtarget motion control.

Implementation and displacement self-sensing of a 4-DOF piezoelectric micromanipulator

This paper reports the development and displacement self-sensing of a new four degrees-of-freedom (DOF) piezoelectric micromanipulator. In particular, each micromanipulator arm can move along the clamping and vertical directions, constructing with two degrees of freedom, and two micromanipulator arms exhibit four degrees of freedom. Thus, it improves operational flexibility. Meanwhile, the self-sensing method avoids additional external sensors when detecting output displacements. The piezoelectric micromanipulator is devised based on the transverse inverse piezoelectric effect of two sets of vertical spatial crossings. Static and dynamic characteristics are analyzed via finite element optimization of geometric parameters. Then, a displacement self-sensing method based on charge integration is proposed. This method measures the generated charge on the clamping arm surface from the piezoelectric wafer deformation under the driving voltage. A self-sensing circuit is designed to obtain the surface charge of the clamping arm. Then, several experiments are conducted to test the micromanipulator. The maximum displacements of the designed micromanipulator are about 66.29 μm and 63.09 μm along clamping and vertical directions. Moreover, output displacements, response time, and inherent frequencies obtained based on the self-sensing method agree well with those with laser sensors. In addition, an operation application for micro-shaft assembly is presented, demonstrating the grasping and docking operations of the micro-shaft in the clamping and vertical directions.

Significantly improved weldability in laser welding of additively manufactured haynes 230 superalloys by tailoring microstructure

Owing to restrictions on forming dimensions, laser powder bed fusion (LPBF) components will continue to require laser welding in the future. The post-weld thermal cracking of LPBF-Haynes 230 superalloys has become a key issue hindering their assembly in service. In this study, it was found that both the continuous TCP phase and M5Si3 silicides near the crack have a large interface strain with the matrix. Replacing the C and Si atoms with B atoms at the crack reduces the melting point of the carbides and silicides at the grain boundaries (GBs), thereby inducing solidification cracking under the residual tensile stress in the weld waist. The weldability of the alloy is influenced by the grain characteristics of the base metal (BM). Compared to parallel welds, vertical welds are inherited from the BM and exhibit smaller grains. Moreover, by reducing the heat treatment (HT) time and temperature, the grain size and grain misorientation of the BM are reduced and inherited into the weld. The GB area of the weld increases by 37% and the GB energy decreases by 7.3%, increasing the resistance to crack extension. In addition, the decreased HT temperature inhibits the carbide growth at the GBs, thereby reducing the interface strain between the matrix and carbides in the heat-affected zone and correspondingly its cracking sensitivity. This study provides theoretical guidance for improving the laser weldability of LPBF superalloys and will help accelerate the successful application of LPBF superalloy assemblies in engines.

Droplet evaporation on superhydrophobic surfaces

Over the last decades, a fabulous variety of synthetic superhydrophobic surfaces have been created, offering unique anti-wetting properties. A significant focus for these surfaces has been on their stay-dry and self-cleaning properties. However, unless in a saturated environment, water droplets lose mass through evaporation and this itself is a field of significant interest, which is illustrated by a flood of recent studies on surface contamination and potential surface transmission of infection by evaporating sessile droplets during the Covid-19 pandemic. Superhydrophobic surfaces alter a droplet's contact with a substrate and the surrounding environment, thus changing pinning and heat transfer properties. The droplet shape also alters the space into which vapor can diffuse. Despite the many excellent reviews on superhydrophobic surfaces, there does not appear to have been a focus on the overlap with evaporating sessile droplets. Here, we address this gap by outlining the diffusion-limited sessile droplet evaporation theory, applications on patterned superhydrophobic surfaces, effect of evaporative cooling on drop evaporation rates, and practical applications of drop evaporation on superhydrophobic surfaces, such as nanoparticle assembly, biomedical assay, analytical chemistry, and crystallization applications. Finally, we provide our personal views of possible future directions in these overlapping areas.

Exploitation of the SoilPRO® (SP) apparatus to measure soil surface reflectance in the field: Five case studies

The SoilPRO® (SP) is an assembly designed to acquire soil reflectance information in the field without disturbing the soil surface, and regardless of atmospheric and solar radiation conditions. This paper summarizes five case studies in which the SP assembly was used for different applications. The case studies consisted of: (1) generating surface spectral measurements under any atmospheric condition; (2) comparing the performance of the SP to the traditional bare fiber method for vicarious calibration of hyperspectral satellite sensors; (3) assessing water repellency of a soil surface governed by organic matter hydrophobicity; (4) spatial prediction of the rate of water infiltration into the soil profile as governed by the soil surface seal; and (5) using the SP apparatus to measure soil surface reflectance in South Shetland Island, Antartica under severe weather conditions. The case studies included calculation of spectral quality, prediction accuracy and measurement stability. The paper discusses each of the cases in detail and concludes that the SP (or similar assembly) is the best way to measure the reflectance of the original soil surface in the field. In the first case study, the spectrum collected by the SP under daily changing illumination was shown to be stable relative to the traditional measurement methods of contact probe or bare fiber. The second case study indicated that use of the SP for vicarious calibration is much more efficient (in terms of time and stability) than ground-truth practice over a large area, and in the third case study, the SP was able to assess a soil surface property governed by organic matter hydrophobicity better than the contact probe, which destroys the soil surface organic seal. A similar achievement was gained in the fourth case study, providing a better assessment of the water-infiltration rate into the soil. In the fifth case study, the SP demonstrated impressive high-quality acquisition of soil surface reflectance with a very low sun angle over the South Pole. Based on these case studies and the high quality of the data generated by the SP in the field, we suggest building, in parallel to the classical soil spectral libraries generated in the laboratory, field soil spectral libraries that will preserve the soil surface properties scanned in the field. We anticipate the development of more applications for the SP assembly based on the capabilities shown in this paper.