Tunable Architecture Research Articles

LPBF Manufactured Functionally Graded Lattice Structures Obtained by Graded Density and Hybrid Poisson's Ratio.

The additive manufacturing (AM) of innovative lattice structures with unique mechanical properties has received widespread attention due to the capability of AM processes to fabricate freeform and intricate structures. The most common way to characterize the additively manufactured lattice structures is via the uniaxial compression test. However, although there are many applications for which lattice structures are designed for bending (e.g., sandwich panels cores and some medical implants), limited attention has been paid toward investigating the flexural behavior of metallic AM lattice structures with tunable internal architectures. The purpose of this study was to experimentally investigate the flexural behavior of AM Ti-6Al-4V lattice structures with graded density and hybrid Poisson’s ratio (PR). Four configurations of lattice structure beams with positive, negative, hybrid PR, and a novel hybrid PR with graded density were manufactured via the laser powder bed fusion (LPBF) AM process and tested under four-point bending. The manufacturability, microstructure, micro-hardness, and flexural properties of the lattices were evaluated. During the bending tests, different failure mechanisms were observed, which were highly dependent on the type of lattice geometry. The best response in terms of absorbed energy was obtained for the functionally graded hybrid PR (FGHPR) structure. Both the FGHPR and hybrid PR (HPR) structured showed a 78.7% and 62.9% increase in the absorbed energy, respectively, compared to the positive PR (PPR) structure. This highlights the great potential for FGHPR lattices to be used in protective devices, load-bearing medical implants, and energy-absorbing applications.

High-power tunable dual-wavelength diode laser with a composite external cavity

A high-power tunable dual-wavelength composite external cavity architecture obtained by means of a holographic grating and a volume Bragg grating is proposed and demonstrated. The tunable frequency difference of the dual-wavelength output is from 0.41 THz to 3.89 THz. We obtain an output power of 2.1 W when the frequency difference is 1.86 THz. The side-mode suppression ratio of more than 29 dB is suppressed over the entire tunable dual-wavelength output range. The two corresponding wavelengths of the dual-wavelength output basically maintain the same intensity with the smallest power difference of only 0.10%.

Antiviral Polymers: A Review.

Polymers, due to their high molecular weight, tunable architecture, functionality, and buffering effect for endosomal escape, possess unique properties as a carrier or prophylactic agent in preventing pandemic outbreak of new viruses. Polymers are used as a carrier to reduce the minimum required dose, bioavailability, and therapeutic effectiveness of antiviral agents. Polymers are also used as multifunctional nanomaterials to, directly or indirectly, inhibit viral infections. Multifunctional polymers can interact directly with envelope glycoproteins on the viral surface to block fusion and entry of the virus in the host cell. Polymers can indirectly mobilize the immune system by activating macrophages and natural killer cells against the invading virus. This review covers natural and synthetic polymers that possess antiviral activity, their mechanism of action, and the effect of material properties like chemical composition, molecular weight, functional groups, and charge density on antiviral activity. Natural polymers like carrageenan, chitosan, fucoidan, and phosphorothioate oligonucleotides, and synthetic polymers like dendrimers and sialylated polymers are reviewed. This review discusses the steps in the viral replication cycle from binding to cell surface receptors to viral-cell fusion, replication, assembly, and release of the virus from the host cell that antiviral polymers interfere with to block viral infections.

Biodegradable, biomimetic, and nanonet-engineered membranes enable high-flux and highly-efficient oil/water separation

Porous membranes with fascinating super-wettable surface and tunable porous architecture for oil-water separation have been developed rapidly, however, the serious secondary marine pollution caused by the non-degradable defectiveness of membranes themselves is still a thorny problem. Herein, we create an eco-friendly membrane with biomimetic cobweb-like nanostructure via assembling two-dimensional bacterial cellulose nanonets on the starch nanofibrous membrane on a large scale. The obtained novel composite membranes exhibit integrated properties of sub-micron pore size, ultrahigh porosity, superhydrophilicity, and underwater superoleophobicity, stemming from the synergistic effect of the hydrated nanonet-skin-layer and porous starch matrix. By virtue of the narrow-distributed sub-micron pores, ultrahigh porosity, and ultrathin thickness, the resulting membrane shows outstanding performance of excellent separation efficiency (up to 99.996%), high percolation flux (maximum of 15968 L m−2 h−1), well surpassing the conventional microfiltration membranes. More significantly, with the advantage of biodegradability and anti-oil-fouling property, the membrane could serve as the robust platform for long-term wastewater remediation.

Implementation and integration of image processing blocks in a real-time bottle classification system

A practical solution to the problems caused by the water, air, and soil pollution produced by the large volumes of waste is recycling. Plastic and glass bottle recycling is a practical solution but sometimes unfeasible in underdeveloped countries. In this paper, we propose a high-performance real-time hardware architecture for bottle classification, that process input image bottles to generate a bottle color as output. The proposed architecture was implemented on a Spartan-6 Field Programmable Gate Array, using a Hardware Description Language. The proposed system was tested for several input resolutions up to 1080 p, but it is flexible enough to support input video resolutions up to 8 K. There is no evidence of a high-performance bottle classification system in the state-of-the-art. The main contribution of this paper is the implementation and integration of a set of dedicated image processing blocks in a high-performance real-time bottle classification system. These hardware modules were integrated into a compact and tunable architecture, and was tested in a simulated environment. Concerning the image processing algorithm implemented in the FPGA, the maximum processing rate is 60 frames per second. In practice, the maximum number of bottles that can be processed would be limited by the mechanical aspects of the bottle transportation system.

Recent Advancements in the Fabrication of Functional Nanoporous Materials and Their Biomedical Applications.

Functional nanoporous materials are categorized as an important class of nanostructured materials because of their tunable porosity and pore geometry (size, shape, and distribution) and their unique chemical and physical properties as compared with other nanostructures and bulk counterparts. Progress in developing a broad spectrum of nanoporous materials has accelerated their use for extensive applications in catalysis, sensing, separation, and environmental, energy, and biomedical areas. The purpose of this review is to provide recent advances in synthesis strategies for designing ordered or hierarchical nanoporous materials of tunable porosity and complex architectures. Furthermore, we briefly highlight working principles, potential pitfalls, experimental challenges, and limitations associated with nanoporous material fabrication strategies. Finally, we give a forward look at how digitally controlled additive manufacturing may overcome existing obstacles to guide the design and development of next-generation nanoporous materials with predefined properties for industrial manufacturing and applications.

Amorphization of Pseudocapacitive T−Nb2O5 Accelerates Lithium Diffusivity as Revealed Using Tunable Isomorphic Architectures

AbstractIntercalation pseudocapacitance can combine capacitor‐like power densities with battery‐like energy densities. Such surface‐limited behavior requires rapid diffusion where amorphization can increase solid‐state diffusivity. Here intercalation pseudocapacitive materials with tailored extents of amorphization in T‐Nb2O5 are first reported. Amorphization was characterized with WAXS, XPS, XAFS, and EPR which suggested a peroxide‐rich (O22−) surface that was consistent with DFT predictions. A series of tunable isomorphic architectures enabled comparisons while independently varying transport parameters. Through process of elimination, solid‐state lithium diffusion was identified as the dominant diffusive‐constraint dictating the maximum voltage sweep rate for surface‐limited kinetics (vSLT), termed the Surface‐Limited Threshold (SLT). The vSLT increased with amorphization however stable cycling required crystalline T‐Nb2O5. A current‐response model using series‐impedances well‐matched these observations. This perspective revealed that amorphization of T‐Nb2O5 enhanced solid‐state diffusion by 12.2 % and increased surface‐limitations by 17.0 % (stable samples). This approach enabled retaining 95 % lithiation capacity at ∼800 mV s−1 (1,600 C‐rate equivalent).

Aziridine-Capped Poly(ethylene glycol) Brush Copolymers with Tunable Architecture as Versatile Cross-Linkers for Adhesives

Aziridine-Capped Poly(ethylene glycol) Brush Copolymers with Tunable Architecture as Versatile Cross-Linkers for Adhesives

Inside Back Cover: Kinetics‐Regulated Interfacial Selective Superassembly of Asymmetric Smart Nanovehicles with Tailored Topological Hollow Architectures (Angew. Chem. Int. Ed. 12/2022)

A kinetics-regulated cooperative polymerization induced interfacial superassembly strategy is used by Biao Kong and co-workers in their Research Article (e202200240) to construct a series of asymmetric hollow porous composites with tunable diameters, architectures, and compositions. Owing to their excellent photothermal conversion performance and unique nanostructures, the resulting nanoparticles can be utilized as NIR light triggered nanovehicles with controllable cargo release.

Kinetics‐Regulated Interfacial Selective Superassembly of Asymmetric Smart Nanovehicles with Tailored Topological Hollow Architectures

AbstractHollow nanoparticles featuring tunable structures with spatial and chemical specificity are of fundamental interest. However, it remains a significant challenge to design and synthesize asymmetric nanoparticles with controllable topological hollow architecture. Here, a versatile kinetics‐regulated cooperative polymerization induced interfacial selective superassembly strategy is demonstrated to construct a series of asymmetric hollow porous composites (AHPCs) with tunable diameters, architectures and components. The size and number of patches on Janus nanoparticles can be precisely manipulated by the precursor and catalyst content. Notably, AHPCs exhibit excellent photothermal conversion performance under the irradiation of a near infrared (NIR) laser. Thus, AHPCs are utilized as NIR light‐triggered nanovehicles and cargos can be controllably released. In brief, this versatile superassembly approach offers a streamlined and powerful toolset to design diverse asymmetric hollow porous composites.

Kinetics-Regulated Interfacial Selective Superassembly of Asymmetric Smart Nanovehicles with Tailored Topological Hollow Architectures.

Hollow nanoparticles featuring tunable structures with spatial and chemical specificity are of fundamental interest. However, it remains a significant challenge to design and synthesize asymmetric nanoparticles with controllable topological hollow architecture. Here, a versatile kinetics-regulated cooperative polymerization induced interfacial selective superassembly strategy is demonstrated to construct a series of asymmetric hollow porous composites (AHPCs) with tunable diameters, architectures and components. The size and number of patches on Janus nanoparticles can be precisely manipulated by the precursor and catalyst content. Notably, AHPCs exhibit excellent photothermal conversion performance under the irradiation of a near infrared (NIR) laser. Thus, AHPCs are utilized as NIR light-triggered nanovehicles and cargos can be controllably released. In brief, this versatile superassembly approach offers a streamlined and powerful toolset to design diverse asymmetric hollow porous composites.

Tunable, Asynchronous, and Nanopower Baseband Receiver for Charging and Wakeup of IoT Devices

This article proposes a novel ultra-low power, tunable, and asynchronous baseband architecture for joint radio-frequency (RF) wakeup and charging receivers. The designed system switches between the wakeup and charging operations based on the type of the received RF signal. To our knowledge, the proposed system is the first of a kind that introduces multiple power states to reduce the energy consumption by sequentially activating minimal components required for RF wakeup or charging. The fabricated prototype, using off-the-shelf components, features a sensitivity of −40 dBm, a bit rate of 500 bps, and a current consumption of 225 nA at a bias voltage of 2.6 V in the listening state. Current consumption is estimated at 3.225 and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$13.725~\mu \text{A}$ </tex-math></inline-formula> while processing the preamble and bit sequence, respectively. The address detector is powered OFF during charging to reduce the system’s current consumption to 150 nA. Our experimental results show that shutting down the address detector during charging reduces charging time and allows charging from received power levels that are as low as −6 dBm. We demonstrate that operating the detector with multiple power modes reduces its current consumption and enhances its noise immunity when compared to conventional address detectors with two power modes of operation.

One-Step Water-Induced Phase Separation Simultaneously Triggering Polymer Solidification and Polyelectrolyte Complexation for Porous Ultrafiltration Membranes.

Functional additives have been widely utilized for the membrane structure modulation and performance improvement during the nonsolvent-induced phase separation process, but the resulted membranes easily suffer from additives' inhomogeneous dispersity and compatibility with the polymer matrix. Herein, a facile and robust strategy, i.e., one-step water-induced phase separation, was proposed for the preparation of polyelectrolytes-contained composite membranes. Polyanion (dopamine modified polyacrylic acid) and polycation (quaternized chitosan paired with bis(trifluoromethane-sulfonyl)imide) were first premixed in dimethyl sulfoxide and used as polyelectrolyte additives in a polysulfone (PSF) solution, and then a uniform PSF-based casting solution was readily obtained. During the solvent-water exchange process, polymer solidification and polyelectrolyte complexation were simultaneously triggered, in situ generating a polyelectrolyte complex fixed within the membrane matrix. Ultrafiltration membranes with hierarchical structures were notably tailored through altering the concentration, molecular weight, and type of polyelectrolytes. The obtained membrane exhibited a water flux of 672 L·m-2·h-1, three times over the raw PSF membrane, while almost maintaining high bovine serum albumin (BSA) rejection. This work paves a straightforward and convenient path for the preparation of composite membranes with tunable architecture and properties.

Nickel cobalt sulfide coated iron nickel selenide hierarchical nanosheet arrays toward high-performance supercapacitors

Tailoring the electronic structure of nanomaterials by constructing core–shell heterostruture is a compelling strategy to design novel electrode materials with modified physiochemical properties for supercapacitors with improved performance. Herein, for the first time, we in situ fabricate iron nickel selenide (FeNiSe2)@nickel cobalt sulfide (Ni4.5Co4.5S8) core–shell nanosheet arrays on carbon cloth by an electrodeposition approach and a selenization treatment. This three-dimensional hierarchcial porous framework formed by plentiful interconnected nanosheets can expose numerous redox active sites with varied oxidation states and provide a conductive and porous skeleton for rapid ion/electrolyte ions transport. Benefiting from its modulated electronic structure and synergetic effect of metal-like FeNiSe2 and Ni4.5Co4.5S8, the as-synthesized FeNiSe2@Ni4.5Co4.5S8 electrode displays a large specific capacity of 236.9 mAh g−1 at 1 A g−1, remarkable rate capability with 80.6% capacity retention at 20 A g−1, and stable cyclic performance, which are superior to those of pure FeNiSe2 and Ni4.5Co4.5S8 electrodes. Besides, the assembled FeNiSe2@Ni4.5Co4.5S8//porous carbon hybrid supercapacitor device offers an energy density of 69.0 Wh kg−1 at 799.2 W kg−1, and exceptional cycling stability with 91.2% capacity retention after 10,000 cycles. This work offers a synthetic strategy to explore core–shell electrode materials with tunable architecture and morphology for high-performance energy storage devices.

Light-based 3D bioprinting of bone tissue scaffolds with tunable mechanical properties and architecture from photocurable silk fibroin

Three-dimensional (3D) bioprinting based on digital light processing (DLP) offers unique opportunities to prepare scaffolds that mimic the architecture and biomechanical properties of human tissues. Limited availability of biocompatible and biodegradable bioinks amenable for DLP-bioprinting is an impediment in this field. This study presents a bioink prepared from silk fibroin (SF) tailored for DLP bioprinting. Photocurable methacrylated-SF (SF-MA) was synthesized with 67.3% of methacrylation. Physical characterization of rheological and mechanical properties revealed that the 3D printed hydrogels of SF-MA (spanning from 10 to 25 wt%) exhibit bone tissue-like viscoelastic behavior and compressive modulus ranging from ≈12 kPa to ≈96 kPa. The gels exhibited favorable degradation (≈48 to 91% in 21 days). This SF-MA bioink afforded the printing of complex structures, with high precision. Pre-osteoblasts were successfully encapsulated in 3D bioprinted SF-MA hydrogels with high viability. 15% SF-MA DLP bioprinted hydrogels efficiently supported cell proliferation with favorable cell morphology and cytoskeletal organization. A progressive increase in cell-mediated calcium deposition up to 14 days confirmed the ability of the gels to drive osteogenesis, which was further augmented by soluble induction factors. This work demonstrates the potential of silk fibroin-derived bioinks for DLP-based 3D bioprinting of scaffolds for tissue engineering.

Tunable Spun Fiber Constructs in Biomedicine: Influence of Processing Parameters in the Fibers' Architecture.

Electrospinning and wet-spinning have been recognized as two of the most efficient and promising techniques for producing polymeric fibrous constructs for a wide range of applications, including optics, electronics, food industry and biomedical applications. They have gained considerable attention in the past few decades because of their unique features and tunable architectures that can mimic desirable biological features, responding more effectively to local demands. In this review, various fiber architectures and configurations, varying from monolayer and core-shell fibers to tri-axial, porous, multilayer, side-by-side and helical fibers, are discussed, highlighting the influence of processing parameters in the final constructs. Additionally, the envisaged biomedical purposes for the examined fiber architectures, mainly focused on drug delivery and tissue engineering applications, are explored at great length.

YOLO-MSFG: Toward Real-Time Detection of Concealed Objects in Passive Terahertz Images

Passive terahertz (THz) systems can perform the perspective imaging of objects concealed underneath clothing on the human body without a radiometric emitter. In this study, a linear-array passive THz imaging system was designed to realize highly efficient push-broom imaging. However, the acquired THz images are contaminated by severe striping and random noise, which greatly hampers object detection. Therefore, this paper aims to report a dedicated deep learning network for the automatic, accurate, and real-time detection of concealed objects in passive THz images. The main work of this research is threefold. First, a bilateral filter is integrated into a convolutional neural network (CNN) to generate a space-range tunable learning architecture. Second, a space-range grid combined with a geometric transformation matrix is designed to provide a core unit for multi-scale filtering and geometric (MSFG) augmentation. Finally, the one-stage YOLOv5 detector is improved to YOLOv5I by refining the granularity of its prediction units. The proposed approach was tested on onsite passive THz images acquired from various scenes, and the results demonstrate that the proposed MSFG augmentation method can significantly improve the detection accuracy of all the candidate CNNs on the passive THz images. Among them, the YOLOv5I-MSFG was found to exhibit the best performance via a comprehensive assessment of its real-time ability and detection accuracy; the time consumption per frame was found to be <inline-formula> <tex-math notation="LaTeX">$\sim 53$ </tex-math></inline-formula> ms on the configured platform, and the accuracies of one-class and two-class detection were found to reach 93.49&#x0025; and 90.76&#x0025;, respectively.

Critical review of nucleic acid nanotechnology to identify gaps and inform a strategy for accelerated clinical translation.

With numerous recent advances, the field of therapeutic nucleic acid nanotechnology is now poised for clinical translation supported by several examples of FDA-approved nucleic acid nanoformulations including two recent mRNA-based COVID-19 vaccines. Within this rapidly growing field, a new subclass of nucleic acid therapeutics called nucleic acid nanoparticles (NANPs) has emerged in recent years, which offers several unique properties distinguishing it from traditional therapeutic nucleic acids. Key unique aspects of NANPs include their well-defined 3D structure, their tunable multivalent architectures, and their ability to incorporate conditional activations of therapeutic targeting and release functions that enable diagnosis and therapy of cancer, regulation of blood coagulation disorders, as well as the development of novel vaccines, immunotherapies, and gene therapies. However, non-consolidated research developments of this highly interdisciplinary field create crucial barriers that must be overcome in order to impact a broader range of clinical indications. Forming a consortium framework for nucleic acid nanotechnology would prioritize and consolidate translational efforts, offer several unifying solutions to expedite their transition from bench-to-bedside, and potentially decrease the socio-economic burden on patients for a range of conditions. Herein, we review the unique properties of NANPs in the context of therapeutic applications and discuss their associated translational challenges.

Design and Evaluation of a Tunable PUF Architecture for FPGAs

FPGA-based Physical Unclonable Functions (PUF) have emerged as a viable alternative to permanent key storage by turning effects of inaccuracies during the manufacturing process of a chip into a unique, FPGA-intrinsic secret. However, many fixed PUF designs may suffer from unsatisfactory statistical properties in terms of uniqueness, uniformity, and robustness. Moreover, a PUF signature may alter over time due to aging or changing operating conditions, rendering a PUF insecure in the worst case. As a remedy, we propose CHOICE , a novel class of FPGA-based PUF designs with tunable uniqueness and reliability characteristics. By the use of addressable shift registers available on an FPGA, we show that a wide configuration space for adjusting a device-specific PUF response is obtained without any sacrifice of randomness. In particular, we demonstrate the concept of address-tunable propagation delays, whereby we are able to increase or decrease the probability of obtaining “ 1 ”s in the PUF response. Experimental evaluations on a group of six 28 nm Xilinx Artix-7 FPGAs show that CHOICE PUFs provide a large range of configurations to allow a fine-tuning to an average uniqueness between 49% and 51%, while simultaneously achieving bit error rates below 1.5%, thus outperforming state-of-the-art PUF designs. Moreover, with only a single FPGA slice per PUF bit, CHOICE is one of the smallest PUF designs currently available for FPGAs. It is well-known that signal propagation delays are affected by temperature, as the operating temperature impacts the internal currents of transistors that ultimately make up the circuit. We therefore comprehensively investigate how temperature variations affect the PUF response and demonstrate how the tunability of CHOICE enables us to determine configurations that show a high robustness to such variations. As a case study, we present a cryptographic key generation scheme based on CHOICE PUF responses as device-intrinsic secret and investigate the design objectives resource costs, performance, and temperature robustness to show the practicability of our approach.

Alcohol hydroxides regulate the growth of Ni-Co layered double hydroxides on carbon fiber cloth as supercapacitor electrode materials

There is a need to design and fabricate Ni-Co layered double hydroxides (Ni-Co LDHs) with high specific capacity, rate capability, and energy density for use as supercapacitor electrode materials. In this study, Ni-Co LDHs are directly grown on the flexible carbon fiber cloth (CFC) substrate by low-carbon alcohol/water solvothermal method. It is found that the morphology of Ni-Co LDHs changes from a wire-like structure to a lamellar structure because of the increased number of alcoholic hydroxyl groups, and the wire-like structure is more favorable for charge transfer and ion diffusion. The number of alcoholic hydroxyl groups has a greater impact on the morphological and electrochemical properties of Ni-Co LDHs compared with the n-propanol content. The Ni-Co LDH@CFC with well cycling stability can be obtained at a n-propanol/water volume ratio of 6:4 and a Ni/Co molar ratio of 1:1. The specific capacity reaches 1102 C g−1 at 2 A g−1 and 70% of the initial capacitance can be retained at 30 A g−1. A button-type asymmetric supercapacitor (ASC) Ni-Co LDH@CFC//AC with an energy density of 39 Wh kg−1 and a power density of 1450 W kg−1 has been successfully fabricated. This work may provide insights into the preparation of high-performance electrode materials with tunable architectures by regulating the number of alcoholic hydroxyl groups.