Assembly Applications Research Articles

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.

Brilliant non-iridescent structural colors of hierarchical photonic films by hydrophobic substrates assembly design

Hierarchical structure designs can maximize the application of structural materials on multi-dimensional scale from a limited choice. Mimicking this performance is a great challenge, especially in optical structures. Here, a hierarchical structural-colored film with highly ordered periodic layers and amorphous array layers was designed by a simple one-step confined self-assembly procedure based on hydrophobic substrates, which shows an excellent optical effect. The highly ordered periodic layers could act as a specific wavelength mirror-like reflectance, which enhanced the coherent scattering of light in the amorphous arrays, resulting in higher color visibility. The intricate interaction of light over hierarchical structures at different length scales has profound significance for the application of complex optical assemblies.

Peptide-Based Optical/Electronic Materials: Assembly and Recent Applications in Biomedicine, Sensing, and Energy Storage.

The unique optical and electronic properties of living systems are impressive. Peptide-based supramolecular self-assembly systems attempt to mimic these properties by preparation optical/electronic function materials with specific structure through simple building blocks, rational molecular design, and specific kinetic stimulation. From the perspective of building blocks and assembly strategies, the unique optical and electronic properties of peptide-based nanostructures, including peptides self-assembly and peptides regulate the assembly of external function subunits, are systematically reviewed. Additionally, their applications in biomedicine, sensing, and energy storage are also highlighted. This bioinspired peptide-based function material is one of the hot candidates for the new generation of green intellect materials, with many advantages such as biocompatibility, environmental friendliness, and adjustable morphology.

A Temporal Coherent Topology Optimization Approach for Assembly Planning of Bespoke Frame Structures

We present a computational framework for planning the assembly sequence of bespoke frame structures. Frame structures are one of the most commonly used structural systems in modern architecture, providing resistance to gravitational and external loads. Building frame structures requires traversing through several partially built states. If the assembly sequence is planned poorly, these partial assemblies can exhibit substantial deformation due to self-weight, slowing down or jeopardizing the assembly process. Finding a good assembly sequence that minimizes intermediate deformations is an interesting yet challenging combinatorial problem that is usually solved by heuristic search algorithms. In this paper, we propose a new optimization-based approach that models sequence planning using a series of topology optimization problems. Our key insight is that enforcing temporal coherent constraints in the topology optimization can lead to sub-structures with small deformations while staying consistent with each other to form an assembly sequence. We benchmark our algorithm on a large data set and show improvements in both performance and computational time over greedy search algorithms. In addition, we demonstrate that our algorithm can be extended to handle assembly with static or dynamic supports. We further validate our approach by generating a series of results in multiple scales, including a real-world prototype with a mixed reality assistant using our computed sequence and a simulated example demonstrating a multi-robot assembly application.

Swarms of modular satellites decentralized guidance and target assignment strategy

This paper presents a decentralized guidance and target assignment (DGTA) strategy for reconfiguring swarms made up of hundreds of modules that have limited communication capabilities. This strategy provides a decentralized onboard computation method to address both near-optimal target assignment and collision-free trajectory planning for swarms of modules. To effectively estimate the transfer cost between modules and targets for target assignment, a multilayer perceptron (MLP) is developed via the backward generation method. The decentralized target assignment problem is solved by greedy algorithm according to the result of the efficient estimating solver. A decentralized model predictive control approach is proposed to guide swarm modules towards their assigned targets, while avoiding collisions with other modules. The feasibility of this guidance framework has been demonstrated through rigorous theoretical analysis. Numerical experiment confirms that the MLP-based method shows an accurate and real-time advantage for estimating transfer cost. Furthermore, the DGTA strategy has been shown to possess robustness and generalization ability, as evidenced by its successful application in a pinpoint assembly task involving 125 and 182 modules. The simulation results confirm the feasibility of this approach for in-orbit assembly application.

Sequestration of Drugs from Biomolecular and Biomimicking Environments: Spectroscopic and Calorimetric Studies

The binding of drugs to nucleic acids, proteins, lipids, amino acids, and other biological receptors is necessary for the transportation of drugs. However, various side effects may also originate if the bound drug molecules are not dissociated from the carrier, especially with the aid of non-toxic agents. The sequestration of small drug molecules bound to biomolecules is thus central to counter issues related to drug overdose and drug detoxification. In this article, we aim to present several methods used for the dissociation of small drug molecules bound to different biological and biomimicking assemblies under in vitro experimental conditions. To this effect, the application of various molecular assemblies, like micelles, mixed micelles, molecular containers, like β-cyclodextrin, cucurbit[7]uril hydrate, etc., has been discussed. Herein, we also try to shed light on the driving forces underlying such sequestration processes through spectroscopic and calorimetric techniques.

Assembly and pseudocapacitive electrode materials application of octamolybdates based coordination polymers

AbstractA new octamolybdates based Cu‐organic polymer, [Cu2(mbix)2]2[Mo8O26] (mbix=1,3‐bis(imidazol‐1‐ylmethyl) benzene), abbreviated as Cu‐Mo8, was hydrothermally synthesized and characterized by routine method. Single‐crystal X‐ray diffraction analysis shows that {Mo8} as template and linker induce and promote the formation and connection of quadcore planetary loop (Cu4mbix4) to form the 2D planetary plane, then are stacked by van der Waals forces to stabilize the whole structure. Electrochemical results show that compound Cu‐Mo8 as electrode materials for supercapacitors exhibits the better supercapacitor performance of ca. 592.2 F g−1 at 1 A g−1, along with great cycling stability, which enriches POMs chemistry in the supercapacitor field.

Recent Progress on Cyclic Peptides' Assembly and Biomedical Applications.

Cyclic peptides are important building blocks for forming functional structures and have been applied in various fields. Considering the significant structural and functional roles of cyclic peptides in materials science and the attributed biophysical advantages, we provide an overview of cyclic peptide types that can self-assemble to form nanotubes, recent progress in stimuli-triggered cyclic peptide assembly, and methods to construct peptide and polymer conjugates based on cyclic peptides with alternative chirality. Specifically, we highlight the roles that stimuli-triggered cyclic peptides and their conjugates play in biomedical applications. Recent progress in other cyclic peptides acting as gelators in drug delivery and biomedicine are also summarized. These cyclic peptides with self-assembly properties are expected to act as adaptive systems for drug delivery and selective disease targeting.

Bioinspired Macroporous Materials of MXene Nanosheets: Ice-Templated Assembly and Multifunctional Applications.

Biological macroporous materials, such as stems of the plants and bone of the animals, possess outstanding properties for powerful guarantee of creatures' survival through the well-aligned architecture constructed from limited components. Transition metal carbides or nitrides (MXenes), as novel 2D assemblies, have attracted numerous attentions in various applications due to their unique properties. Therefore, mimicking the bioinspired architecture with MXenes will boost the development of human-made materials with unparalleled properties. Freeze casting has been widely applied to fabricate bioinspired MXene-based materials and achieve the assembly of MXene nanosheets into 3D forms. This process solves the inherent restacking problems of MXenes, simultaneously preserving the unique properties of MXenes with a physical process. Here, the ice-templated assembly of MXene in terms of the freezing processes and their potential mechanisms is summarized. In addition, applications of MXene-based materials in electromagnetic interference shielding and absorption, energy storage and conversion, as well as piezoresistive pressure sensors are also reviewed. Finally, the current challenges and bottlenecks of ice-templated assembly of MXene are further discussed to guide the development of bioinspired MXene-based materials.

Modular Cloning by Golden Gate Assembly and Possible Application in Pathway Design.

Preparation of expression vectors using conventional cloning strategies is laborious and not suitable for the design of metabolic pathways or enzyme cascades, which usually requires the preparation of a vector library to identify productive clones. Recently, Modular Cloning as a novel cloning technique in synthetic biology has been developed. Modular Cloning relies on Golden Gate assembly and supports preparation of individual expression vectors in one-step and one-pot reactions, thus allowing rapid generation of vector libraries. A number of Modular Cloning toolkits for specific applications has been established, providing a collection of distinct genetic elements such as promoters, ribosome binding sites and tags, that can be combined individually in one-step using defined fusion sites. Modular Cloning has been successfully applied to generate various strains for producing value-added compounds. This was achieved by orchestrating complex pathways involving up to 20 enzymes. Due to the novelty of the genetic approach, industrial applications are still rare. In addition, some applications are limited due to the lack of high-throughput screening methods. This shifts the bottleneck from library preparation to screening capacity and needs to be addressed by future developments to pave the path for the establishment of Modular Cloning in industrial applications.

A review of digital twin intelligent assembly technology and application for complex mechanical products

A review of digital twin intelligent assembly technology and application for complex mechanical products

Magnetic synergism in Janus particles—Relevance to synthetic advances, materialistic properties and their niche applications

Multifunctional nanoparticles are emerging materials of interest as they outperform conventional nanoparticles. The advancing field of Janus nanoparticles relates to a dissymmetrical system with biphasic geometry and different chemical compositions. They combine the properties of two independent materials and so render superior properties than their symmetrical counterparts. Tailoring Janus materials with magnetic components find an extensive role in the biomedical to environmental applications owing to magnetic synergism. Unlike non-magnetic systems, Magnetic Janus particles (MJPs) facilitate facile separation, purification, recycling and complex superstructure formation, well-tuned by externally applied fields. The presence of magnetic components allows stimuli-responsive orientation, self-assembly, directionality and targeted site-specific action that make them appropriate candidates for targeted delivery and therapy, biomarkers, imaging, tracking and controlled-dynamics. This review article examines various MJP types, synthesis routes, anisotropy types, characterization methods, directed assembly, and related applications in relation to their magnetic behaviour. Along with the current difficulties and their potential solutions, the recent advancements in this area—such as the one-pot synthetic approach, biocompatible multifunctionalization, and combinatorial action as vectors, biomarkers, and theranostic agents—are highlighted.

Biosynthesis, Assembly, and Biomedical Applications of High-Performance Engineered Proteins.

Engineered structural proteins, mimicking the structure and function of well-characterized natural proteins, are of great interest for diverse applications due to their outstanding mechanical performance and hierarchical structures. Broad efforts have been devoted to developing novel toolsets of genetically engineered structural proteins to explore advanced protein-based materials. With the rational design and structural optimization of artificially structural proteins and the improved biosynthetic methods, artificial protein assemblies have demonstrated outstanding mechanical performance comparable to those of natural protein materials, showing promising biomedical applications. In this Review, we outline recent advances in the fabrication of high-performance protein materials, highlighting the roles of biosynthesis, structural modification, and assembly in optimizing the materials' properties. The relationship between hierarchical structures and the mechanical performance of these recombinant structural proteins is discussed in detail. We emphasize the biomedical applications of high-performance structural proteins and their assemblies in the fields of high-strength protein fibers and adhesives. Finally, we discuss the trends and perspectives for the development of structural protein-based materials.