Design Of Devices Research Articles

Study of dielectric and interfacial properties of functional biopolymer-based electrolyte with enhanced conductivity for energy storage application

This study investigates sodium (Na+) ion-conductive biopolymer blend electrolytes with glycerol as a plasticizer for energy storage. Through FTIR, impedance spectroscopy, transference number measurement (TNM), and linear sweep voltammetry (LSV), we identify an optimal film for electric double layer capacitor (EDLC) application. Glycerol induces notable changes in polymer-salt interaction, evidenced by FTIR band shifts reflecting increased free ions. Impedance measurements show reduced bulk resistance with optimal plasticizer content, emphasizing the system's suitability for energy storage. The system exhibits high real permittivity relative to imaginary at lower frequencies, attributing to glycerol's dielectric constant and small bulk resistance. Loss tangent (tanδ) and Argand plots reveal the dominant ion conduction mechanism. Electrochemical assessments support the suitability of the film for EDLC applications, featuring a favorable transference number (tion = 0.94) and high decomposition voltage (2.6V). Cyclic voltammetry (CV) curves demonstrate effective EDLC device design with significant capacitance adaptability across varying scan rates (5.946 F/g to 24.074 F/g).

Site-selective core/shell deposition of tin on multi-segment nanowires for magnetic assembly and soldered interconnection

The field of nanotechnology continues to grow with the ongoing discovery and characterization of novel nanomaterials with unconventional size-dependent properties; however, the ability to apply modern manufacturing strategies for practical device design of these nanoscale structures is significantly limited by their small size. Although interconnection has been previously demonstrated between nanoscale components, such approaches often require the use of expensive oxidation-resistant noble metal materials and time-consuming or untargeted strategies for welded interconnection such as laser ablation or plasmonic resonance across randomly oriented component networks. In this work, a three-segment gold–nickel–gold nanowire structure is synthesized using templated electrodeposition and modified via monolayer-directed aqueous chemical reduction of tin solder selectively on the gold segments. This core/shell nanowire structure is capable of directed magnetic assembly tip-to-tip and along substrate pads in network orientation. Upon infrared heating in a flux vapor atmosphere, the solder payload melts and establishes robust and highly conductive wire–wire joints. The targeted solder deposition strategy has been applied to various other multi-segment gold/nickel nanowire configurations and other metallic systems to demonstrate the capability of the approach. This core/shell technique of pre-loading magnetically active nanowires with solder material simplifies the associated challenges of size-dependent component orientation in the manufacture of nanoscale electronic devices.

Exploring optoelectronic and thermal characteristics of Janus MoSeTe and WSeTe monolayers under mechanical strain

This paper reveals the effect of external strain on the electronic, thermal and optical properties of Janus MSeTe (M=Mo, W) using first principles. Phonon spectrum calculations confirm the dynamic stability of the system. Biaxial stretching can effectively modulate its thermal properties. Uniaxial, biaxial and shear strains modulate the band structure, structural parameters, averaged differential charge density and optical properties of the MSeTe system to different degrees. The increase of compressive and shear strains leads to a gradual decrease of the band gap and triggers a semiconductor-metal phase transition at the critical point. The intrinsic system exhibits strong light absorption in the visible and ultraviolet regions, while strain induces a redshift of the light-absorbing edge, which enhances the response to the infrared and visible wavelength bands. These findings provide a theoretical basis and application potential for the design of optoelectronic devices and thermoelectric materials.

Modeling the manganese deposit on the BP (111)-(2×2) surface: Density functional theory studies

The structural, electronic, and magnetic properties of the manganese (Mn) adsorption and incorporation into the boron phosphide (BP) in surface (111) – periodicity (2 × 2) structure have been investigated using spin-polarized first-principles total-energy calculations. The exchange-correlation energies are treated within the generalized gradient approximation. The magnetic properties have been studied by considering different coverages and magnetic configurations. The Mn adsorption and incorporation range from ¼ to 1 monolayer (ML), with results displaying: Ferromagnetic (FM), antiferromagnetic (AFM), and non-magnetic (NM) behavior at low, intermediate, and high coverages, respectively. The electronic properties are explored considering the total density of states (DOS) and the projected density of states (PDOS). It is noted that the contribution of the Mn-d orbital modifies the metallicity of the surface. The results show that the most favorable structure is the 1 Mn ML adsorption, with an AFM alignment and a magnetic moment of 0 μB/atom. The material exhibits metallicity at the first monolayer induced by manganese, while the lower internal layers are semiconductors. Finally, the charge density distribution corroborates the surface metallic phase, which indicates that the proposed material can be helpful in the design of new spintronic devices.

A bladeless wind-tunnel generator based on a flutter-driven triboelectric nanogenerator with on-demand micro-structuring

With the unremitting demand for renewable energy sources, triboelectric nanogenerators as efficient micro-energy, particularly wind-energy harvesting devices, have garnered increased attention. This study introduces an innovative wind flutter-driven triboelectric nanogenerator (WF-TENG). It employs an on-demand integrated design of a "mortise and tenon" microstructure and is assembled in a "negative-positive-negative" configuration mimicking a "corrugated paper" macrostructure, effectively converting wind energy into electrical energy. The porous crosslinked ethyl cellulose/polyethyleneimine positive friction layer and the bionic rose-petal-like fluorinated ethylene propylene negative friction layer are assembled to form a miniaturized "mortise and tenon" structure, which greatly improves the charge transfer efficiency. Surprisingly, due to the collaborative structural design on micro-/macro-scale, WF-TENG elevates the breakthrough power density of WF-TENG to 455.932 mW cm−2. Further, the integrated-equipped bladeless wind tunnel generator, assembled with the WF-TENG array, utilizes airflow disturbances to produce high-frequency flutter-driven frictional motions. This system outputs up to 7.5 kV at a startup wind speed of 7.9 m s−1 and maintains stable performance for 60 days. Application experiment substantiates the ample electrical energy collected by the bladeless wind tunnel generator for powering an indoor formaldehyde purifier demonstrates a high formaldehyde purification rate of 94 %, providing new insights for the design and applications of novel micro-energy harvesting devices.

“In My Experience…Medical Device Design & Innovation in Shoulder Replacements”

The author reviews his experience with a novel process of designing and bringing a medical device to market.

Synthesis and morphological characterization of CaSO$$_{4}$$: low-temperature Raman spectroscopy analysis of vibrational modes

AbstractThis study delves into the synthesis of CaSO$$_{4}$$ 4 materials using the Pechini and sol-gel methods, followed by heat treatment up to 900 $$^{\circ }$$ ∘ C. X-ray analysis discerned distinct phases, with one method yielding pure orthorhombic anhydrite and the other predominantly producing a mixture of orthorhombic anhydrite and bassanite. Scanning electron microscopy (SEM) showcased homogeneous columnar morphologies for the anhydrite samples and irregularly sized particles for the alternative method. Photoluminescence (PL) measurements demonstrated emissions in the visible range (approximately 400 nm to 700 nm) with differences noted between synthesis methods. Low-temperature Raman spectroscopy (20 K to room temperature) unveiled unique vibrational modes, notably with the orthorhombic phase of anhydrite exhibiting the most intense peak at 1017 cm$$^{-1}$$ - 1 . These powders, intended for thin film applications, bear significance in electronics, optoelectronics, and nanotechnology. A thorough comprehension of their structural and vibrational properties at the microscopic level is paramount for material and device design and optimization.

Moisture‐induced High‐quality Perovskite Film in Air for Efficient Solar Cells

The quality of perovskite light‐harvesting layer is known to be the most critical factor for the performance of perovskite solar cells (PSCs). We herein adopt a facile ambient air‐aging process (AAP, 20‐30% RH) to realize the fabrication of high‐quality Cs0.15FA0.75MA0.1PbI3 perovskite films, thereby upgrading device performance. We find that the perovskite crystallinity after AAP for 10 d is greatly intensified, with large grain size and preferred crystal orientation along (110) and (220) planes. Comparative studies on the Ag‐based devices employing the perovskite films upon exposing to different atmospheres i.e. dry N2, dry O2, N2 & H2O (20‐30% RH), and ambient air (20‐30% RH) demonstrate that H2O molecules in air rather than O2 molecules induce an effective defect‐passivation that holds the multiple functions in enhancing the quality of perovskite film, inhibiting the nonradiative recombination, prolonging the carrier lifetime and improving the energy level matching, etc. Moreover, the positive effect of H2O in ambient atmosphere on cell performance is irreversible and remains even if moisture escapes. Finally, the average PCE of device based on the AAP‐induced film is increased from 18.24±1.49 to 21.34±0.76, with the champion PCE up to 22.60%. Also, the device with AAP exhibits better moisture resistance capability. This work offers a viable AAP‐induced route for the perovskite films with superb optoelectronic properties that can be subsequently extend to the design and construction of other photovoltaic devices for practical application.This article is protected by copyright. All rights reserved.

Addressing multi-molecule field-coupled nanocomputing for neural networks with SCERPA

The molecular field-coupled nanocompunting (molFCN) technology encodes the information in the charge distribution of electrostatically coupled molecules, making it an exciting solution for future beyond-CMOS low-power electronics. Recent literature has shown that multi-molecule molFCN enables the design of devices with tailored unconventional characteristics, such as majority voters working as artificial neurons. This work presents a multi-molecule molFCN neuron model based on the weighted-inputs formulation to estimate molFCN neurons behavior. Then, the introduced model is used to design each neuron of molFCN circuits working as neural networks. In particular, we propose a molFCN neural network operating as an input pattern classifier. The results show the model aptitude in predicting the logic output values for individual neurons and, consequently, entire networks. The model accuracy has been evaluated by comparing the results from the neuron mathematical model with those obtained from the circuit-level simulations conducted with the SCERPA tool. Overall, this study highlights the strategic use of diverse molecules in molFCN layouts, customizing circuit operations, and expanding design possibilities for specific molFCN device functioning.

Promises and technological prospects of two-dimensional Rashba materials

The Rashba spin–orbit coupling effect, primarily arising from structural-inversion asymmetry in periodic crystals, has garnered considerable attention due to its tunability and potential applications in spintronics. Its capability to manipulate electron spin without an external magnetic field opens new avenues for spintronic device design, particularly in semiconductor technology. Within this framework, 2D Rashba materials hold special interest due to their inherent characteristics, which facilitate miniaturization and engineering capabilities. In this Perspective article, we provide an overview of recent advancements in the research of 2D Rashba materials, aiming to offer a comprehensive understanding of the diverse manifestations and multifaceted implications of the Rashba effect in material science. Rather than merely presenting a list of materials, our approach involves synthesizing various viewpoints, assessing current trends, and addressing challenges within the field. Our objective is to bridge the gap between fundamental research and practical applications by correlating each material with the necessary advancements required to translate theoretical concepts into tangible technologies. Furthermore, we highlight promising avenues for future research and development, drawing from insights gleaned from the current state of the field.

Effects of external fields and structural parameters on third harmonic generation of GaAs/AlGaAs Manning-like double quantum well structure

In this theoretical work, we investigate how external fields like as electric, magnetic, and intense laser fields, as well as structural factors, affect the third harmonic generation (THG) coefficient of an AlGaAs/GaAs Manning-like double quantum well heterostructure. To achieve our goals, we numerically solve the time-independent Schrödinger equation using the diagonalization approach with the effective mass approximation and then derive the subband energy levels and corresponding wave functions of the structure. After that, we derive the mathematical expression of the THG coefficient by using the compact density matrix method. According to our results, the resonance peaks of the THG coefficient show shifting to the high-energy region with an increase in the field’s magnitude in cases where external fields (electric, magnetic, and intense laser) are applied separately. At the same time, increasing the depth (width) of the quantum well structure causes the THG peaks to shift to the high (low) energy region. We believe that the findings from this search will have a substantial impact on existing experimental device designs and applications.

Unveiling the geometrical and mechanical properties of Σ3 (111) grain boundaries in Ni-based alloys: From interfacial insights

Understanding the properties of interfaces and grain boundaries is pivotal for advancing the design and performance of modern materials and devices. The mechanical strength and durability of materials are significantly influenced by the integrity of these interfaces and grain boundaries. In this study, we employ density functional theory calculations to investigate the geometries, electronic properties, and mechanical behaviors of Σ3 (111) grain boundaries in Ni, AlNi3, and FeNi3 systems. Result reveals that these grain boundaries exhibit trigonal, hexagonal, and hexagonal close-packed structures with minimal bond length distortions, attributed to specific misorientation angles of 60°. They also demonstrate bonding characteristics akin to their corresponding polycrystalline bulk materials, indicating stability and twist character with anti-phase boundaries. Evaluation of grain boundary energetics indicates low energy values and stability across the studied systems. Furthermore, we conduct a detailed examination of the interfacial grain boundary structures of Σ3 (111) Ni/AlNi3 and Σ3 (111) Ni/FeNi3, revealing trigonal closed space configurations with twist character and anti-phase boundaries. Electron localization in interfacial regions suggests a metallic nature of interfacial bonds, supported by density of state calculations and positive Cauchy pressure. Assessment of mechanical properties indicate ductile behavior due to structural heterogeneity, moderate anisotropy. Overall, present study underscores the enhanced mechanical properties resulting from heterogeneity, offering promise for future applications in advanced materials and devices. Additionally, a comparative analysis with highlights the advancements and contributions of this study to the existing body of knowledge.

Design and evaluation of a versatile text input device for virtual and immersive workspaces

ABSTRACT While headsets dedicated to mixed reality are increasingly considered to virtualize workspaces in the office, the keyboard remains mostly unchanged and nevertheless is still envisioned as an interface for common professional activities heavily demanding in text entry. However, unlike headsets, a keyboard is intrinsically limited to immobile context during its use, due to the need for physical support. In this article, we investigate a radical change in the structural shape of the keyboard, switching from the plane to a cube, allowing users to fully benefit from their whole environment by entering text in a much wider variety of contexts. We designed a cubic layout based on the QWERTY and results from two user studies to define the best holding position as well as fingers preferences and reachability to the cubic shape. Then, we conducted two subsequent user studies and one longitudinal case study to compare and evaluate typing skill transfer from the keyboard, learning curve, fingers usage, usability, and workload in various contexts. The cubic-shaped text entry device finally showed its versatility with users having similar performances while standing with a mixed-reality headset or sitting in front of a laptop, and an input speed from an expert reaching 55.1 wpm.

Design and Verification of Experimental Device for Pressurized Bubbling Absorption and Transport Characteristics in Vacuum Environment

Design and Verification of Experimental Device for Pressurized Bubbling Absorption and Transport Characteristics in Vacuum Environment

Chemical hazard assessment toward safer electrolytes for lithium-ion batteries.

Commercialization of rechargeable lithium-ion (Li-ion) batteries has revolutionized the design of portable electronic devices and is facilitating the current transition to electric vehicles. The technological specifications of Li-ion batteries continue to evolve through the introduction of various high-risk liquid electrolyte chemicals, yet critical evaluation of the physical, environmental, and human health hazards of these substances is lacking. Using the GreenScreen for Safer Chemicals approach, we conducted a chemical hazard assessment (CHA) of 103 electrolyte chemicals categorized into seven chemical groups: salts, carbonates, esters, ethers, sulfoxides-sulfites-sulfones, overcharge protection additives, and flame-retardant additives. To minimize data gaps, we focused on six toxicity and hazard data sources, including three empirical and three nonempirical predictive data sources. Furthermore, we investigated the structural similarities among selected electrolyte chemicals using the ChemMine tool and the simplified molecular input line entry systeminputs from PubChem to evaluate whether chemicals with similar structures exhibit similar toxicity. The results demonstrate that salts, overcharge protection additives, and flame-retardant additives contain the most toxic components in the electrolyte solutions. Furthermore, carbonates, esters, and ethers account for most flammability hazards in Li-ion batteries. This study supports the complementary use of quantitative structure-activity relationship modelsto minimize data gaps and inconsistencies in CHA. Integr Environ Assess Manag 2024;00:1-14. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Assessment of a continuous passive motion assistive device in dogs following stifle surgery

Canine rehabilitation optimizes recovery and the quality of life in dogs with musculoskeletal conditions or after surgery. Achieving proper range of motion (ROM) is vital post-stifle surgery, often accomplished through manual therapy and active exercises. We investigated the mechanical performance of a continuous passive motion (CPM) device for dogs and its potential use in canine rehabilitation therapy.In the ethical review process, our research was accepted to be evaluated in a sample of four dogs that had undergone left stifle surgery. Each dog underwent four sessions with the device at three different speeds. Results showed the device replicated extension angles close to goniometer measurements used in manual therapy. Flexion was also achieved, but not to the same extent. A force threshold stopped the device, avoiding discomfort in dogs with restricted ROM. Dog-specific factors like body position, opposition to movement, limb size, stage of recovery, haircoat, and discomfort, appeared to influence device operation. Mechanical improvements to allow for enhanced flexion are recommended in future CPM device designs, including a resistance threshold that could be adjusted for individual dogs and stages of healing. This study serves as a foundation for future advancements in canine rehabilitation systems. A canine CPM device may provide an affordable option to improve ROM. This could be beneficial for dog owners, who may not be comfortable with manual therapy, to assist with home rehabilitation exercises.

Boosting flexible electronics with integration of two‐dimensional materials

AbstractFlexible electronics has emerged as a continuously growing field of study. Two‐dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high‐performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high‐performance and high‐sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design.

Science challenges and research opportunities for plasma applications in microelectronics

Low-temperature plasmas (LTPs) are essential to manufacturing devices in the semiconductor industry, from creating extreme ultraviolet photons used in the most advanced lithography to thin film etching, deposition, and surface modifications. It is estimated that 40%–45% of all process steps needed to manufacture semiconductor devices use LTPs in one form or another. LTPs have been an enabling technology in the multidecade progression of the shrinking of device dimensions, often referred to as Moore’s law. New challenges in circuit and device design, novel materials, and increasing demands to achieve environmentally benign processing technologies require advances in plasma technology beyond the current state-of-the-art. The Department of Energy Office of Science Fusion Energy Sciences held a workshop titled Plasma Science for Microelectronics Nanofabrication in August 2022 to discuss the plasma science challenges and technical barriers that need to be overcome to continue to develop the innovative plasma technologies required to support and advance the semiconductor industry. One of the key outcomes of the workshop was identifying a set of priority research opportunities (PROs) to focus attention on the most strategic plasma science challenges to address to benefit the semiconductor industry. For each PRO, scientific challenges and recommended strategies to address those challenges were identified. This article summarizes the PROs identified by the workshop participants.

Dynamic Response of Ionic Current in Conical Nanopores.

Ionic current rectification (ICR) of charged conical nanopores has various applications in fields including nanofluidics, biosensing, and energy conversion, whose function is closely related to the dynamic response of nanopores. The occurrence of ICR originates from the ion enrichment and depletion in conical pores, whose formation is found to be affected by the scanning rate of voltages. Here, through time-dependent simulations, we investigate the variation of ion current under electric fields and the dynamic formation of ion enrichment and depletion, which can reflect the response time of conical nanopores. The response time of nanopores when ion enrichment forms, i.e., at the "on" state is significantly longer than that with the formation of ion depletion, i.e., at the "off" state. Our simulation results reveal the regulation of response time by different nanopore parameters including the surface charge density, pore length, tip, and base radius, as well as the applied conditions such as the voltage and bulk concentration. The response time of nanopores is closely related to the surface charge density, pore length, voltage, and bulk concentration. Our uncovered dynamic response mechanism of the ionic current can guide the design of nanofluidic devices with conical nanopores, including memristors, ionic switches, and rectifiers.

Non-reciprocal optical bistability of sandwiched structure containing magnetic Weyl semimetals

We investigate non-reciprocal optical bistability (OB) of sandwiched structure comprising of two magnetic Weyl semimetal (WSM) layers and a nonlinear layer. The resonant tunneling mode in the sandwiched structure with a nonlinear layer creates favorable conditions for the emergence of OB. Besides, the inherent non-reciprocal nature of WSM enables non-reciprocal transmission of OB in the absence of an external magnetic field. By employing the transfer matrix method, we simulate the OB curves for forward and backward propagations, as well as analyze the non-reciprocity of OB. Furthermore, the impacts of various parameters on non-reciprocal OB are comprehensively discussed. The results demonstrate that the non-reciprocal OB curve and the width of the isolation of the non-reciprocal OB can be tuned by adjusting the thickness and the axial vector of the WSM, the temperature as well as the incident angle. This work would provide crucial insights for the design of high-performance non-reciprocal devices.