Recent discovery of ferroelectricity in doped HfO2 has reignited research interest in the ferroelectric field-effect transistor (FeFET) as emerging embedded nonvolatile memory with the potential for neuro-inspired computing. This paper reviews two major aspects for its application in neuro-inspired computing: ferroelectric devices as multilevel synaptic devices and the circuit primitive design with FeFET for in-memory computing. First, the authors survey representative FeFET-based synaptic devices. Then, the authors introduce 2T-1FeFET synaptic cell design that improves its in situ training accuracy to approach software baseline. Then, the authors introduce the FeFET drain–erase scheme for array-level operations, which makes the in situ training feasible for FeFET-based hardware accelerator. Finally, the authors give an outlook on the future 3D-integrated 2T-1FeFET design.

We report the synthesis of a novel polymer gel electrolyte primarily based on cellulose extracted from wood along with gelatin, polyacrylic acid (PAA) and potassium hydroxide (KOH) added as additives in minute amounts in various stages. We also study and report the variation of ionic conductivity with variation of various additives. We found that, with variation of additives to hydrogel, its stability and degree of crystallinity are varied. The results were confirmed using x-ray diffraction and Fourier transform infrared spectra studies. An average best ionic conductivity of 96.89mS/cm was reported for a hydrogel: gelatin: PAA: KOH system, which is one of the best reported values of ionic conductivity for gel electrolytes.

Self-assembled vertical heteroepitaxial nanostructures (VHN) in the complex oxide field have fascinated scientists for decades because they provide degrees of freedom to explore in condensed matter physics and design-coupled multifunctionlities. Recently, of particular interest is the perovskite-spinel-based VHN, covering a wide spectrum of promising applications. In this review, fabrication of VHN, their growth mechanism, control, and resulting novel multifunctionalities are discussed thoroughly, providing researchers a comprehensive blueprint to construct promising VHN. Following the fabrication section, the state-of-the-art design concepts for multifunctionalities are proposed and reviewed by suitable examples. By summarizing the outlook of this field, we are excitedly expecting this field to rise with significant contributions ranging from scientific value to practical applications in the foreseeable future.

Owing to lack of a definitive correlation between carbon supports and catalytic activity of single-atom Fe-active sites, rational design and preparation of single-atom Fe catalysts have so far been elusive. Herein we designed and prepared one-dimensional core–shell nanostructured single-atom Fe catalysts, in which carbon nanofibers and carbon nanotubes with different crystallinities and electrical conductivities were used as supports to host single-atom Fe-active sites. It was found that the carbon supports with higher electrical conductivity accelerate charge transfer and enhance the oxygen reduction reaction (ORR) activity of single-atom Fe-active sites as well as the ORR durability of the final catalyst.

Gelatin/poly(epichlorohydrin-co-ethylene oxide) [GL : PECO] composites are synthesized in a one-step process by the incorporation of elastic PECO and diclofenac. [GL : PECO] fibers are prepared by Forcespinning®. GL : PECO fibers are capable of diclofenac, by conjugation via a labile amide linkage. Fourier transform infrared spectroscopy (FTIR) results confirmed the chemical reactions and hydrogen bonds between gelatin, PECO, and diclofenac. Diclofenac drug release from GL : PECO fibers are measured for 15 days and prolonged drug release is observed. The cell viability is studied with NIH/3T3 and excellent results are observed. The sustained drug release and cytotoxicity results reveal that GL : PECO fibers could be promising substitutes for skin tissue engineering, wound healing, and drug delivery.

A review is given of the future device processing needs for Ga2O3 power electronics. The two main devices employed in power converters and wireless charging systems will be vertical rectifiers and metal oxide semiconductor field effect transistors (MOSFETs). The rectifiers involve thick epitaxial layers on conducting substrates and require stable Schottky contacts, edge termination methods to reduce electric field crowding, dry etch patterning in the case of trench structures, and low resistance Ohmic contacts in which ion implantation or low bandgap interfacial oxides are used to minimize the specific contact resistance. The MOSFETs also require spatially localized doping enhancement for low source/drain contact resistance, stable gate insulators with acceptable band offsets relative to the Ga2O3 to ensure adequate carrier confinement, and enhancement mode capability. Attempts are being made to mitigate the absence of p-type doping capability for Ga2O3 by developing p-type oxide heterojunctions with n-type Ga2O3. Success in this area would lead to minority carrier devices with better on-state performance and a much-improved range of functionality, such as p-i-n diodes, Insulated Gate Bipolar Transistors, and thyristors.

Offering a unique suite of mechanical, physical, and chemical properties, bulk metallic glasses (BMGs) show significant promise as engineering materials. Unfortunately, most BMGs exhibit low tensile ductility at ambient temperature that limits their use as structural (load-bearing) materials. To overcome this problem, BMG composites (BMGCs) containing a second phase are being developed for improving ductility by controlling the mechanics of shear band nucleation and growth in the glassy matrix, which is the primary mode of failure in these materials. This review describes some recent developments in BMGCs and discusses the influence of the type of second phase on mechanical behavior.

We introduce CRYSTAL, a multi-agent AI system for crystal-structure phase mapping. CRYSTAL is the first system that can automatically generate a portfolio of physically meaningful phase diagrams for expert-user exploration and selection. CRYSTAL outperforms previous methods to solve the example Pd-Rh-Ta phase diagram, enabling the discovery of a mixed-intermetallic methanol oxidation electrocatalyst. The integration of multiple data-knowledge sources and learning and reasoning algorithms, combined with the exploitation of problem decompositions, relaxations, and parallelism, empowers AI to supersede human scientific data interpretation capabilities and enable otherwise inaccessible scientific discovery in materials science and beyond.

All-polymer solar cells composed of binary blends of donor poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene-)-2–6-diyl)] (PBDTTT-CT ), and acceptor polymers naphthalene diimide-selenophene copolymer (PNDIS-HD) and perylene diimide-selenophene copolymer (PPDIS) had power conversion efficiencies (PCEs) of 1.3 and 2.1%, respectively. Ternary blend solar cells composed of [PBDTTT-CT][PNDIS-HD]1−x[PPDIS]x at 75 wt% PPDIS had a PCE of 3.2%, which is about a 50%–140% enhancement compared with the binary blend devices. Equality of the ternary blend short-circuit current to the sum of those of the binary blend devices, among other results, provided evidence of a parallel-like bulk heterojunction mechanism in the ternary blend solar cells. These results provide the first example of enhanced performance in ternary blend all-polymer solar cells.

Lithium (Li) dendrite formation in Li-metal batteries (LMBs) remains a key obstacle preventing LMBs from their widespread application. This study focuses on the role of the stress field in the Li electrodeposits formation and growth. Coupled electrochemical and mechanical phase-field model (PFM) is used to investigate electrodeposited Li evolution under different conditions. The PFM results, using both the anisotropic elastic properties of Li and the random delivery of Li-ions through the solid electrolyte interface, show a significant local stress development indicating a direct correlation between the stress field and the origin of the undesired Li filaments initiation.

Nanotechnology has been considered as a promising strategy for diagnosis and treatment of various diseases. However, the stability and circulation times of the conventional nano-carriers, such as liposomes and micelles, are still unsatisfied. Perfluorocarbons (PFCs) are biologic inert synthetic materials, which are highly hydrophobic and have a tendency to self-aggregation. Additionally, PFCs themselves can act as 19F magnetic resonance imaging agents and oxygen carriers. Thus, the construction of the fluorinated carriers will not only improve the stability of the carriers, but also endow them with additional functions. Here we review the recent advances of PFC-based nanosystems for diagnosis and treatment of diseases.

Poly[sulfur-random-1,3-diisopropenylbenzene (DIB)] copolymers synthesized via inverse vulcanization form electrochemically active polymers used as cathodes for high-energy density Li–S batteries, capable of enhanced capacity retention (1005 mAh/g at 100 cycles) and lifetimes of over 500 cycles. In this prospective, we demonstrate how analytical electron microscopy can be employed as a powerful tool to explore the origins of the enhanced capacity retention. We analyze morphological and compositional features when the copolymers, with DIB contents up to 50% by mass, are blended with carbon nanoparticles. Replacing the elemental sulfur with the copolymers improves the compatibility and interfacial contact between active sulfur compounds and conductive carbons. There also appears to be improvements of the cathode mechanical stability that leads to less cracking but preserving porosity. This compatibilization scheme through stabilized organosulfur copolymers represents an alternative strategy to the nanoscale encapsulation schemes which are often used to improve the cycle life in high-energy density Li–S batteries.

This article presents a comprehensive overview of currently available research on bioimplantable energy harvesters, with a specific focus on their fabrication and issue of biocompatibility. Both the achievements and limitations of the field are pointed out from the standpoint of materials science and engineering as directions for future research. Particular attention is paid to the controversy over the use of lead-based or lead-free piezoelectric ceramics in biomedical applications, which is closely related to different temporalities of research on biological conditions. This report is intended to serve as a reference guide for developing the next generation of piezoelectric biomedical devices.

We have studied by electron microscopy and x-ray diffraction techniques the amorphous-to-crystalline phase transition which occurs during annealing of a highly Ge-rich and N-doped amorphous GeSbTe material. The crystallization onset occurs at 380 °C with the diffusion and segregation of Ge followed by the formation of Ge nanocrystals. The GeSbTe face-centered cubic (FCC) crystalline phase only appears at 400 °C. Phase separation occurs because the Ge concentration is well above what can be accommodated by the Ge2Sb2Te5 lattice. The possible formation of a two-phase material should be considered in order to simulate device characteristics and optimize material composition for electronic memory applications.

The fabrication of bimetallic magnetic nanoparticles (NPs) smaller than the size of single magnetic domain is very challenging because of the agglomeration, non-uniform size, and possible complex chemistry at nanoscale. In this paper, we present an alloyed ferromagnetic 4 ± 1 nm thiolated Au/Co magnetic NPs with decahedral and icosahedral shape. The NPs were characterized by Cs-corrected scanning transmission electron microscopy (STEM) and weretheoretically studied by Grand Canonical Monte Carlo simulations. Comparison of Z-contrast imaging and energy dispersive x-ray spectroscopy used jointly with STEM simulated images from theoretical models uniquely showed an inhomogeneous alloying with minor segregation. The magnetic measurements obtained from superconducting quantum interference device magnetometer exhibited ferromagnetic behavior. This magnetic nanoalloy in the range of single domain is fully magnetized and carries significance as a promising candidate for magnetic data recording, permanent magnetization, and biomedical applications.

Photonic crystal nanolasers are fabricated and operated simply, and can be applied as disposable sensors for biomedical applications. They are sensitive to the change with environmental index and surface charge. Functionalizing the nanolaser surface with an antibody, the specific binding of target antigen is detected with a detection limit 2–4 orders lower than that achieved by current standard methods, enzyme-linked immuno-sorbent assay. Nanolasers also detect negatively-charged deoxyribonucleic acid from their emission intensity. This technique requires neither labels nor spectroscopy, which simplifies screening procedures. Its applicability for high-speed detection of endotoxin and for label-fee imaging of living cells are also demonstrated.

The formation of a metastable Cu–Ta solid solution in a mechanically alloyed Cu–10 at.%Ta alloy and its subsequent decomposition during annealing was investigated by atom probe tomography. During annealing, the as-milled Cu-rich alloy undergoes phase separation; Ta atoms diffuse out of the Cu lattice to form Ta clusters and particles along grain boundaries and within the Cu grains. The role of the Ta clusters and the nature of the solid solution as a potential strengthening mechanism for these alloys are discussed.

The magnetic properties of Sr3SnO (SSO) epitaxial thin films prepared under various post-growth annealing treatments are reported. The SSO films are grown on cubic yttria-stabilized zirconia Si (001) platform by pulsed laser deposition. Post-growth vacuum annealing is found to enhance the room-temperature ferromagnetism (RTFM), whereas oxygen annealing reduces it. The results are explained through the oxygen vacancy constituted bound magnetic polarons (BMP) model. An empirical relationship between the extracted BMP concentration and the oxygen vacancy concentration is shown using X-ray photoelectron spectroscopy data. The results indicate a promising way to tune RTFM by manipulating oxygen vacancies and related defects.

Bioengineered hydrogels enable systematic variation of mechanical and biochemical properties, resulting in the identification of optimal in vitro three-dimensional culture conditions for individual cell types. As the scientific community attempts to mimic and study more complex biologic processes, hydrogel design has become multi-faceted. To mimic organ and tissue heterogeneity in terms of spatial arrangement and temporal changes, hydrogels with spatiotemporal control over mechanical and biochemical properties are needed. In this prospective article, we present studies that focus on the development of hydrogels with dynamic mechanical and biochemical properties, highlighting the discoveries made using these scaffolds.

The present study aimed to develop an easy method to synthesis silver nanoparticles (AgNPs) using Allamanda cathartica flower extracts. The phytocompounds converted silver nitrate into AgNPs. UV–visible spectra show the maximum absorbance between 350 and 450 nm and x-ray powder diffraction results reveal AgNPs crystallized in cubic phase. Fourier transform infrared spectrum reveals that phytochemicals act as a reducing, stabilizing, and capping agent. Energy-dispersive spectrum, particle size distribution, and transmission electron microscopy analyses show that the nanoparticles are pure, spherical shaped with size of 39 nm. In addition, AgNPs show significantly antibacterial and antioxidant activity compared with commercial antibiotic. Hence, A. cathartica flower extracts mediated AgNPs which will be a new candidate for biomedical applications.