Fabrication of Ag–ZnO NRs SERS substrates for abamectin detection: the effect of Ag sputtering times and ZnO sol concentrations in seed layer preparation on SERS performance

Journal of Materials Science: Materials in Electronics - In this study, a surface-enhanced Raman scattering (SERS) substrate based on uniform silver nanoparticles/ZnO nanorods arrays (Ag–ZnO...     

Convolutional Neural Network-Based Regression for Predicting the Chloride Ion Diffusion Coefficient of Concrete

The durability performance of reinforced concrete (RC) building structures is significantly affected by the corrosion of the steel reinforcement due to chloride penetration, thus, the chloride ion diffusion coefficient should be investigated through experiments or theoretical equations to assess the durability of an RC structure. This study aims to predict the chloride ion diffusion coefficient of concrete, a heterogeneous material. A convolutional neural network (CNN)-based regression model that learns the condition of the concrete surface through deep learning, is developed to efficiently obtain the chloride ion diffusion coefficient. For the model implementation to determine the chloride ion diffusion coefficient, concrete mixes with w/c ratios of 0.33, 0.40, 0.46, 0.50, 0.62, and 0.68, are cured for 28 days; subsequently, the surface image data of the specimens are collected. Finally, the proposed model predicts the chloride ion diffusion coefficient using the concrete surface image data and exhibits an error of approximately 1.5E−12 /s. The results suggest the applicability of proposed model to the field of facility maintenance for estimating the chloride ion diffusion coefficient of concrete using images.     

Hierarchically Nanoporous 3D Assembly Composed of Functionalized Onion‐Like Graphitic Carbon Nanospheres for Anode‐Minimized Li Metal Batteries

Despite the recent attention for Li metal anode (LMA) with high theoretical specific capacity of ≈ 3860 mA h g^?1, it suffers from not enough practical energy densities and safety concerns originating from the excessive metal load, which is essential to compensate for the loss of Li sources resulting from their poor coulombic efficiencies (CEs). Therefore, the development of high‐performance LMA is needed to realize anode‐minimized Li metal batteries (LMBs). In this study, high‐performance LMAs are produced by introducing a hierarchically nanoporous assembly (HNA) composed of functionalized onion‐like graphitic carbon building blocks, several nanometers in diameter, as a catalytic scaffold for Li‐metal storage. The HNA‐based electrodes lead to a high Li ion concentration in the nanoporous structure, showing a high CE of ≈ 99.1%, high rate capability of 12 mA cm^?2, and a stable cycling behavior of more than 750 cycles. In addition, anode‐minimized LMBs are achieved using a HNA that has limited Li content ( ≈ 0.13 mg cm^?2), corresponding to 6.5% of the cathode material (commercial NCM622 ( ≈ 2 mg cm^?2)). The LMBs demonstrate a feasible electrochemical performance with high energy and power densities of ≈ 510 Wh kg_electrode^?1 and ≈ 2760 W kg_electrode^?1, respectively, for more than 100 cycles.     

A decision model to determine the number of shuttles in a tier-to-tier SBS/RS

Shuttle-based storage and retrieval systems (SBS/RSs), which are designed to increase throughput capacity and flexibility, are a type of automated storage and retrieval system used for lightweight loads. SBS/RSs can increase throughput capacity by using multiple shuttles and elevators as storage and retrieval machines (SRMs). They can also facilitate improvements in flexibility since they are able to adjust the number of SRMs according to transaction demands. Thus, determining the number of shuttles is an important issue in tier-to-tier SBS/RSs. In this paper, a decision model to determine the number of shuttles is proposed. The model is based on the travel time model, and it considers parameters such as the physical configuration, velocity profile and the probability that the shuttle operates a dual command. Finally, the throughput capacity from the travel time model is compared with that from a simulation-based approach in order to verify the effects of the model. In addition, a critical discussion regarding the characteristics of the tier-to-tier system is provided.     

High‐Performance Flexible Photodetectors based on High‐Quality Perovskite Thin Films by a Vapor–Solution Method

Organometal halide perovskites are new light‐harvesting materials for lightweight and flexible optoelectronic devices due to their excellent optoelectronic properties and low‐temperature process capability. However, the preparation of high‐quality perovskite films on flexible substrates has still been a great challenge to date. Here, a novel vapor–solution method is developed to achieve uniform and pinhole‐free organometal halide perovskite films on flexible indium tin oxide/poly(ethylene terephthalate) substrates. Based on the as‐prepared high‐quality perovskite thin films, high‐performance flexible photodetectors (PDs) are constructed, which display a nR value of 81 A W^?1 at a low working voltage of 1 V, three orders higher than that of previously reported flexible perovskite thin‐film PDs. In addition, these flexible PDs exhibit excellent flexural stability and durability under various bending situations with their optoelectronic performance well retained. This breakthrough on the growth of high‐quality perovskite thin films opens up a new avenue to develop high‐performance flexible optoelectronic devices.     

A Flexible Loudspeaker Using the Movement of Liquid Metal Induced by Electrochemically Controlled Interfacial Tension

A flexible liquid metal loudspeaker (LML) is demonstrated consisting of a gallium‐based eutectic liquid metal (Galinstan) and basic aqueous electrolyte (NaOH_(aq)). The LML is driven by liquid metal motion induced by the electrochemically controlled interfacial tension of the Galinstan in NaOH_(aq) electrolyte under an applied alternating current (AC) voltage. The fabricated LML produces sound waves in the human audible frequency band with a sound pressure level of ≈40–50 dB at 1 cm from the device and exhibits mechanical stability under bending deformation with a bending radius of 3 mm. Various sounds can be generated with the LML from a single tone to piano notes and human voices. To understand the underlying mechanism of sound generation by the LML, motion analyses, sound measurements, and electrical characterization are conducted at various frequencies. For the first time, this work suggests a new type of liquid metal‐based electrochemically driven sound generator in the field of flexible acoustic devices that can be applied to future wearable electronics.     

Biocomputing with Nanostructures on Lipid Bilayers

Biocomputation is the algorithmic manipulation of biomolecules. Nanostructures, most notably DNA nanostructures and nanoparticles, become active substrates for biocomputation when modified with stimuli‐responsive, programmable biomolecular ligands. This approach—biocomputing with nanostructures (“nano‐bio computing”)—allows autonomous control of matter and information at the nanoscale; their dynamic assemblies and beneficial properties can be directed without human intervention. Recently, lipid bilayers interfaced with nanostructures have emerged as a new biocomputing platform. This new nano‐bio interface, which exploits lipid bilayers as a chemical circuit board for information processing, offers a unique reaction space for realizing nanostructure‐based computation at a previously unexplored dimension. In this Concept, recent advances in nano‐bio computing are briefly reviewed and the newly emerging concept of biocomputing with nanostructures on lipid bilayers is introduced.     

Thioflavin T‐Amyloid Hybrid Nanostructure for Biocatalytic Photosynthesis

Amyloidogenic peptides can self‐assemble into highly ordered nanostructures consisting of cross β‐sheet‐rich networks that exhibit unique physicochemical properties and high stability. Light‐harvesting amyloid nanofibrils are constructed by employing insulin as a building block and thioflavin T (ThT) as a amyloid‐specific photosensitizer. The ability of the self‐assembled amyloid scaffold to accommodate and align ThT in high density on its surface allows for efficient energy transfer from the chromophores to the catalytic units in a similar way to natural photosystems. Insulin nanofibrils significantly enhance the photoactivity of ThT by inhibiting nonradiative conformational relaxation around the central C? C bonds and narrowing the distance between ThT molecules that are bound to the β‐sheet‐rich amyloid structure. It is demonstrated that the ThT‐amyloid hybrid nanostructure is suitable for biocatalytic solar‐to‐chemical conversion by integrating the light‐harvesting amyloid module (for nicotinamide cofactor regeneration) with a redox biocatalytic module (for enzymatic reduction).     

Highly Sensitive and Stretchable Resistive Strain Sensors Based on Microstructured Metal Nanowire/Elastomer Composite Films

High sensitivity and high stretchability are two conflicting characteristics that are difficult to achieve simultaneously in elastic strain sensors. A highly sensitive and stretchable strain sensor comprising a microstructured metal nanowire (mNW)/elastomer composite film is presented. The surface structure is easily prepared by combining an mNW coating and soft‐lithographic replication processes in a simple and reproducible manner. The densely packed microprism‐array architecture of the composite film leads to a large morphological change in the mNW percolation network by efficiently concentrating the strain in the valley regions upon stretching. Meanwhile, the percolation network comprising mNWs with a high aspect ratio is stable enough to prevent electrical failure, even under high strains. This enables the sensor to simultaneously satisfy high sensitivity (gauge factor ≈81 at >130% strain) and high stretchability (150%) while ensuring long‐term reliability (10 000 cycles at 150% strain). The sensor can also detect strain induced by bending and pressure, thus demonstrating its potential as a versatile sensing tool. The sensor is successfully utilized to monitor a wide range of human motions in real time. Furthermore, the unique sensing mechanism is easily extended to detect more complex multiaxial strains by optimizing the surface morphology of the device.