Conventional Devices Research Articles

Pin penetration depths in the neurocranium using a three-pin head fixation device

In estimated 10–15% of neurosurgical interventions employing a conventional three-pin head fixation device (HFD) the patient’s head loses position due to slippage. At present no scientifically based stability criterion exists to potentially prevent the intraoperative loss of head position or skull fractures. Here, data on the skull penetration depth both on the single and two-pin side of a three-pin HFD are presented, providing scientific evidence for a stability criterion for the invasive three-pin head fixation. Eight fresh, chemically untreated human cadaveric heads were sequentially pinned 90 times in total in a noncommercially calibrated clamp screw applying a predefined force of 270 N (approximately 60 lbf) throughout. Three head positions were pinned each in standardized manner for the following approaches: prone, middle fossa, pterional. Titanium-aluminum alloy pins were used, varying the pin-cone angle on the single-pin side from 36° to 55° and on the two-pin side from 25° to 36°. The bone-penetration depths were directly measured by a dial gauge on neurocranium. The penetration depths on the single-pin side ranged from 0.00 mm (i.e., no penetration) to 6.17 mm. The penetration depths on the two-pin side ranged from 0.00 mm (no penetration) to 4.48 mm. We measured a significantly higher penetration depth for the anterior pin in comparison to the posterior pin on the two-pin side in prone position. One pin configuration (50°/25°) resulted in a quasi-homogenous pin depth distribution between the single- and the two-pin side. Emanating from the physical principle that pin depths behave proportionate to pin pressure distribution, a quasi-homogenous pin penetration depth may result in higher resilience against external shear forces or torque, thus reducing potential complications such as slippage and depressed skull fractures. The authors propose that the pin configuration of 50°/25° may be superior to the currently used uniform pin-cone angle distribution in common clinical practice (36°/36°). However, future research may identify additional influencing factors to improve head fixation stability.

Gesture Controlled Virtual Mouse and Voice Assistant

The Al Virtual Mouse uses computer vision techniques to track hand movements and translates them into cursor movements on the screen. The system is designed user-friendly, allowing users to interact with their computer without the need for a physical mouse. The system is constructed using advanced Python packages like Mediapipe, OpenCV, etc. All i/o activities are physically controlled by a hand motion and a voice assistance. The research uses advanced technologies like machine learning and computer vision techniques, which operates well without the use of any additional computer resources, to recognize hand movements and spoken instruction. The developed system provides an alternative to conventional mouse devices, for individuals with disabilities or those who prefer a more natural way of interacting with their computers.

High Impedance Fault Detection and Localization Using Fully-Connected Convolutional Neural Network: A Deep Learning Approach

The detection and localization of high impedance faults (HIF) in power systems are challenging due to the low fault current magnitude, which often falls below the detection threshold of conventional devices. HIF events introduce harmonics into the network, posing risks to the safety of connected equipment, including the potential for igniting fire which endangers lives and properties. In this study, Emanuel's HIF model was used to generate HIF signatures resembling real HIF events. Model parameters were adjusted to mimic various contact surface impedances. Two datasets were created: 'no-fault' data, simulating the network without HIF, and 'fault' data, incorporating HIF waveforms by simulating single and multiple lines with the HIF model. The faulted line was divided into five segments along the 33 kV line to capture fault signatures at different locations. The generated data, including current waveforms and magnitudes, were processed and divided into an 80:20 ratio for training, validation, and testing using a deep fully connected Convolutional Neural Network for HIF detection and location. The results showed an impressive accuracy rate of 99.44% and 99.78% for detection and location respectively, representing a significant advancement in HIF detection and location, and offering practical applications for enhancing power line safety.

Development of a high intensity focused ultrasound device for bio-samples preparation

A miniaturized, low-cost high-intensity focused ultrasound device is developed for the problems of cross-contamination and uneven sample fragmentation in conventional ultrasound devices. This device generates ultrasonic waves through a concave spherical self-focusing piezoelectric ceramic piece, and creates a cavitation effect in the focusing area to achieve sample fragmentation. The feasibility of the device is demonstrated by physical simulation, then a driving circuit with adjustable power is designed and manufactured to generate 0 ~ 22.4 W acoustic power, and finally paraffin-embedded sample dewaxing experiments are performed to verify the validation of the device. The experimental results show that the dewaxing efficiency and safety of the high-intensity focused ultrasound device is significantly better than those of traditional chemical methods, and this device is comparable with commercial ultrasonic instruments. In summary, the high-intensity focused ultrasound device is expected to be applied in automated nucleic acid extraction and purification equipment and has a broad application prospect in the field of sample pre-processing.

Electrochemical performance of symmetric solid oxide cells employing a Sc-doped SrFeO3-δ-based electrode

Symmetrical solid oxide cells (SSOCs) integrate the capabilities of solid oxide fuel cells and solid oxide electrolysis cells within a symmetric device, which have the advantage of simple fabrication and lower cost compared to conventional devices. Herein, to develop more advanced electrode materials to meet the catalytic activity for different electrode reactions, this study explores Sc-doped Sr0.9Fe0.8Sc0.1Co0.1O3−δ (SFSC) as an SSOC electrode material. Experiments show that Sc doping enhances the crystal stability of Sr0.9Fe0.9Co0.1O3−δ (SFC) in H2 and provides more oxygen vacancies for CO2 adsorption. Electrochemical tests reveal that the SFSC-Gd0.1Ce0.9O1.95 (GDC) electrode offers high power output, high CO2 electrolysis rates, and stability. Specifically, when operated as a fuel cell, the thus fabricated SSOC exhibits a peak power density of 781 mW·cm−2 and a polarization resistance of 0.117 Ω·cm2 at 850 °C, with operational stability over 300 h. Additionally, it reaches a peak current density of 1.96 A·cm−2 at 850 °C for CO2 electrolysis and is stable for 200 h at 0.45 A·cm−2 and 800 °C. Ab initio simulations further reveal a higher probability for oxygen vacancies in SFSC and an improved catalytic dissociation ability relative to Sr0.9Fe0.9Co0.1O3−δ for hydrogen and CO2. The stable and multi-functional SFSC-GDC electrode thus represents a compelling choice for SSOCs, advancing the prospects for efficient and cost-effective energy solutions.

Optical bistability and flip-flop function in feedback Fano laser.

Optical bistability has the potential to emulate the capabilities of electrical flip-flops, offering plenty of applications in optical signal processing. Conventional optical bistable devices operate by altering the susceptibility of a nonlinear medium. This method, however, often results in drawbacks such as large device size, high energy consumption, or long switching times. This work proposes an optical bistable device incorporating strong optical feedback into a Fano laser. This leads to multiple stable states and introduces a region of bistability between the inherent Fano mode and a feedback-induced Fabry-Perot mode. Unlike conventional bistable devices, the Fano system exploits strong field localization in a nanocavity to control the properties of one of the laser mirrors. This configuration means that switching states can be achieved by modulating the mirror's loss rather than changing the susceptibility of the active medium. Importantly, modulation can be implemented locally on a nanocavity, bypassing the need to adjust the entire laser system. This leads to fast flip-flop actions with low energy consumption. The feedback Fano laser can be embodied in a compact microscopic structure, thus providing a promising approach towards integrated all-optical computation and on-chip signal processing.

Mole Fraction and Device Reliability Analysis of Vertical-Tunneling-Attributed Dual-Material Double-Gate Heterojunction-TFET with Si0.7Ge0.3 Source Region at Device and Circuit Level

This paper puts forward a new vertical-tunneling-attributed dual-material double-gate heterojunction-TFET (VTDMDG-HTFET). The device structure of VTDMDG-HTFET includes Si[Formula: see text]Ge[Formula: see text] material for the designing of source region. The mechanism of vertical tunneling in VTDMDG-HTFET provides superior electric field at tunneling interface and leads to improved transfer characteristics. VTDMDG-HTFET also includes metal gate work-function engineering approach to facilitate high ON-current and small OFF-current. Application of high-[Formula: see text] dielectric material HfO2 in the form of gate oxide enhances the capacitive-coupling at channel-source interface. Moreover, the work includes the comparison of proposed VTDMDG-HTFET with the conventional vertical-tunneling based dual-material double-gate-TFET (VTDMDG-TFET). It has been observed from the simulation results that SiGe source-based VTDMDG-HTFET offers better DC characteristics in terms of superior ON-current, smaller OFF-current, steeper subthreshold-slope, lower threshold voltage, higher transconductance along with smaller drain-induced barrier-lowering (DIBL) effects as compared to its counterpart silicon-source-based VTDMDG-TFET. In this work, reliability of VTDMDG-HTFET has also been examined and compared with VTDMDG-TFET in terms of temperature sensitivity and effect of different interface trap charges. The device simulation and investigations have been carried out using technology computer aided design (TCAD) tool. Moreover, device circuit mixed-mode simulation analysis is carried out for conventional and proposed device based resistive load inverters. A comparison is performed between both the inverters in terms of prorogation delay and switching threshold voltages. Further, the mixed mode simulation analysis is also performed for the proposed device based inverter under the influence of different interface trap charges (ITCs). Study shows that reliability performance of the proposed device is better as compared to its counterpart conventional device. Hence, vertical tunneling and SiGe source-based VTDMDG-HTFET can be a better choice for various applications such as analog/RF, analog and digital electronic circuits, energy harvesting, gas-sensing and memory devices.

A Seamless, Large‐Area Silk‐based Interface for Immersive On‐Palm Tactile Feedback

AbstractWearable haptic devices are developed as key components to enhance the highly immersive metaverse experience. However, conventional haptic devices enabling the sensation and interaction with virtual objects are often constrained by their bulky design, tethered operation, and physical interference with the skin, especially when integrated with human hands. In this study, a cross‐interface modification process that achieves the conversion of multilayered silk fibroin films from rigid to soft is reported. This modification is favorable for applications involving large angles and multiple degrees of freedom motions. By applying electrical current through silk‐based electrodes and utilizing a self‐designed circuit, virtual tactile sensations can be generated on the entire palm. The high flexibility, stretchability, tailorable modulus, and water permeability of silk substrates enable the electrotactile devices to maintain their functionalities without impeding fine movements and natural tactile sensations in the hand. This compact electrotactile system serves as a user's new interactive terminal through wireless communications. The intimate contact interfaces reduce the unstable adhesion commonly encountered in electrotactile applications, ensuring consistent sensation during hand motions. These materials design methods and integrated systems represent a significant advancement in fabricating and integrating large‐area soft electronics.

Fully Printable and Reconfigurable Hufu-type Electroluminescent Devices for Visualized Encryption.

Hufu, serving as evidence of imperial authorization in ancient China, comprises two parts in the form of tiger-shaped tallies that only become effective when matched. Drawing inspiration from the concept of Hufu, a reconfigurable electroluminescent (EL) device is designed by separating conventional integral devices into two parts that contain the EL layer (part A) and the transparent electrode (part B), respectively. The key to realizing such strategy is employing an adhesive and stretchable polymer gel composite as the transparent electrodes for the EL devices. The polymer gel composite facilitates robust yet reversible contact between the EL layer and transparent electrode, enabling high-performance and stretchable EL devices that can be readily disassembled and reassembled: the EL devices can maintain ≈81% of their initial luminance after 1000 times of repeated disassembly and reassembly. Moreover, the precursor ink of the polymer gel composite is compatible with a wide variety of coating and printing technologies, such as spin-coating, inkjet printing, dispensing, and brush painting. Importantly, the reconfigurable feature of the devices opens up a new path to encryption display systems, and as a proof-of-concept, EL encrypted password, and content-changeable digital clock are demonstrated.

Power Generation by Thermal Evaporation Based on a Button Supercapacitor.

Thermal evaporation generators exhibit remarkable output performance, sustainability, and economy and, as a result, have attracted considerable interest as a prospective energy-converting technology for harvesting renewable energy. Here, we investigate power generation induced by water evaporation within a button supercapacitor with a simple sandwich structure. For conventional water evaporation devices, the thermodiffusion direction of hydrated ions driven by the Soret effect is opposite to the migration direction of hydrated ions driven by the streaming potential effect during thermal evaporation, which could reduce the output performance of the device. By tuning the thermodiffusion direction to be consistent with the thermal evaporation direction, our button supercapacitor achieves enhanced output performance as high as 674.4 mV, 70.7 mA, and 4.68 mW cm-2 due to the synergistic mechanism of the streaming potential effect and the Soret effect. Moreover, the system could effectively achieve in situ energy generation and storage owing to the device's ability to act as a supercapacitor. Our findings supply a feasible strategy for the synergistic integration of waste energy sources (low-grade waste heat, etc.) to generate electricity.

Electromechanically reconfigurable plasmonic nanoslits for efficient nano-opto-electro-mechanical tuning

Plasmonic metamaterials with strong localized surface plasmon resonances (LSPRs) have been improved by incorporating a nano-opto-electro-mechanical system (NOEMS) for tunable optical and electrical responses. However, conventional NOEMS devices suffer from the inefficient free-space coupling due to the limited design of reconfigurable antennas and the low optical tunability due to electrostatic pull-in of moving parts. In this paper, we propose efficient mid-infrared plasmonic nanoslits with variable nanometer-sized gaps giving rise to broad optical tunability. Our finite element method (FEM) analysis shows that by applying a voltage bias to asymmetric nanoslits supported on dielectric pillars, the gap width can be increased by more than 60 nm from an initial 1 nm. The large change in gap width results in a significant spectral shift in reflectance, while maintaining strong free-space coupling and a constant full width at half maximum (FWHM). We also analyze the effect of geometrical parameters on the nanometer-sized gap width and optical responses. Our nanoslits with simple geometry resulting in efficient optical coupling show promise for improving active metasurfaces and electromechanically tunable plasmonic devices.

Performance investigation of stacked-channel junctionless Tri-Gate FinFET 8T-SRAM cell

Junctionless FinFET devices are a substitute for conventional FinFET devices due to their short channel effects and easy manufacturing at sub 22 nm technology node. The manuscript presents an 8T-SRAM cell based on tri-gate junctionless FinFET technology. The FinFET device is designed with source/drain of Si material and the channel as a stack of Si − Si 0.75 Ge 0.25 − Si. The proposed SRAM cell structure consists of a CMOS inverter with stacked p-FinFETs, improving its performance in terms of noise margin and leakage power consumption. The manuscript investigates the variation of Static Noise Margin (SNM), leakage power dissipation and delay with supply voltage to analyze the sub-threshold operation of SRAM cell. The results reveal that the cascaded p-FinFETs minimize the leakage current owing to the stack effect, resulting in improved noise margin and lower leakage power. The stacked p-FinFET devices based SRAM cell achieves 1.11x read noise margin, 1.11x hold noise margin, −1.08x write noise margin and 57.1% less leakage power compared to conventional SRAM cell at 1.0 V. However, it exhibits more delay due to increased resistance and capacitance of the cascaded transistors. The process variation analysis is also performed to investigate the SNM distribution using monte-carlo simulation by taking 10,000 samples. The results indicate that the SRAM cell structures provide higher than 6σ yield at range of supply voltages.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias

BackgroundVentricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry. ObjectivesThis study examined the efficacy of SGB for treatment/temporization of refractory VT/VF. MethodsThe authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB. ResultsIn total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001). ConclusionsIn the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

Magnonic combinatorial memory

In this work, we consider a type of magnetic memory where information is encoded into the mutual arrangement of magnets. The device is an active ring circuit comprising magnetic and electric parts connected in series. The electric part includes a broadband amplifier, phase shifters, and attenuators. The magnetic part is a mesh of magnonic waveguides with magnets placed on the waveguide junctions. There are amplitude and phase conditions for auto-oscillations to occur in the active ring circuit. The frequency(s) of the auto-oscillation and spin wave propagation path(s) in the magnetic part depends on the mutual arrangement of magnets in the mesh. The propagation path is detected with a set of power sensors. The correlation between circuit parameters and spin wave path is the basis of memory operation. The combination of input/output switches connecting electric and magnetic parts and electric phase shifters constitute the memory address. The output of the power sensors is the memory state. We present experimental data on the proof-of-the-concept experiments on the prototype with three magnets placed on top of a single-crystal yttrium iron garnet Y3Fe2(FeO4)3 (YIG) film. There are three selected places for the magnets to be placed. There is a variety of spin wave propagation paths for each configuration of magnets. The results demonstrate a robust operation with an On/Off ratio for path detection exceeding 35 dB at room temperature. The number of possible magnet arrangements scales factorially with the size of the magnetic part. The number of possible paths per one configuration scales factorial as well. It makes it possible to drastically increase the data storage density compared to conventional memory devices. Magnonic combinatorial memory with an array of 100 × 100 magnets can store all information generated by humankind. Physical limits and constraints are also discussed.

High-Throughput Microfluidic Extraction of Platelet-free Plasma for MicroRNA and Extracellular Vesicle Analysis.

Cell-free RNAs and extracellular vesicles (EVs) are valuable biomarkers in liquid biopsies, but they are prone to preanalytical variabilities such as nonstandardized centrifugation or ex vivo blood degradation. Herein, we report a high-throughput and label-free inertial microfluidic device (ExoArc) for isolation of platelet-free plasma from blood for RNA and EV analysis. Unlike conventional inertial microfluidic devices widely used for cell sorting, a submicrometer size cutoff (500 nm) was achieved which completely removed all leukocytes, RBCs, platelets, and cellular debris based on differential lateral migration induced by Dean vortices. The single-step operation also reduced platelet-associated miRNAs (∼2-fold) compared to centrifugation. We clinically validated ExoArc for plasma miRNA profiling (39 samples) and identified a 7-miRNA panel that detects non-small cell lung cancer with ∼90% sensitivity. ExoArc was also coupled with size exclusion chromatography (SEC) to isolate EVs within 50 min with ∼10-fold higher yield than ultracentrifugation. As a proof-of-concept for EV-based transcriptomics analysis, we performed miRNA analysis in healthy and type 2 diabetes mellitus (T2DM) subjects (n = 3 per group) by coupling ExoArc and ExoArc+SEC with quantitative polymerase chain reaction (RT-qPCR) assay. Among 293 miRNAs detected, plasmas and EVs showed distinct differentially expressed miRNAs in T2DM subjects. We further demonstrated automated in-line EV sorting from low volume culture media for continuous EV monitoring. Overall, the developed ExoArc offers a convenient centrifugation-free workflow to automate plasma and EV isolation for point-of-care diagnostics and quality control in EV manufacturing.

Stretchable Device for Simultaneous Measurements of Contractility and Electrophysiology of Neuromuscular Tissue in the Gastrointestinal Tract.

Devices interfacing with biological tissues can provide valuable insights into function, disease, and metabolism through electrical and mechanical signals. However, certain neuromuscular tissues, like those in the gastrointestinal tract, undergo significant strains of up to 40%. Conventional inextensible devices cannot capture the dynamic responses in these tissues. This study introduces electrodes made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and polydimethylsiloxane (PDMS) that enable simultaneous monitoring of electrical and mechanical responses of gut tissue. The soft PDMS layers conform to tissue surfaces during gastrointestinal movement. Dopants, including Capstone FS-30 and polyethylene glycol, are explored to enhance the conductivity, electrical sensitivity to strain, and stability of the PEDOT:PSS. The devices are fabricated using shadow masks and solution-processing techniques, providing a faster and simpler process than traditional clean-room-based lithography. Tested on ex vivo mouse colon and human stomach, the device recorded voltage changes of up to 300 µV during contraction and distension consistent with muscle activity, while simultaneously recording resistance changes of up to 150% due to mechanical strain. These devices detect and respond to chemical stimulants and blockers, and can induce contractions through electrical stimulation. They hold great potential for studying and treating complex disorders like irritable bowel syndrome and gastroparesis.

Electrophysiological findings in long-term type 1 diabetes patients without diabetic retinopathy using different ERG recording systems

To assess full-field electroretinogram findings in long-term type 1 diabetes patients without diabetic retinopathy. Prospective study including 46 eyes of 23 patients with type 1 diabetes and 46 age-matched healthy eyes evaluated by the RETI-port/scan21 and the portable system RETeval following ISCEV guidelines. The average duration of diabetes was 28.88 ± 8.04 years. In scotopic conditions, using the RETI-port/scan21, diabetic patients showed an increase in b-wave implicit time (IT) (p = 0.017) with the lowest stimuli; a diminished b-wave amplitude (p = 0.005) in the mixed response, an increased IT (p = 0.004) with the high-intensity stimuli and an OP2 increased IT (p = 0.008) and decreased amplitude (p = 0.002). Under photopic conditions, b-wave amplitude was lower (p < 0.001) and 30-Hz flicker response was diminished (p = 0.021). Using the RETeval, in scotopic conditions, diabetic patients showed a reduction in the rod b-wave amplitude (p = 0.009), an increase in a-wave IT with the 280 Td.s stimulus (p = 0.005). OP2 had an increased IT and diminished amplitude (p = 0.003 and p = 0.002 respectively). 16 Td.s flicker showed an increased IT (p = 0.008) and diminished amplitude (p = 0.048). Despite variations in values between both systems, nearly all results displayed positive correlations. Long-term type 1 diabetes patients without diabetic retinopathy exhibit alterations in scotopic conditions, as evidenced by both conventional and portable electroretinogram devices. These findings suggest a modified retinal function, particularly in rod-driven pathways, even in the absence of vascular signs.

A continuous synthesis method of hydroxymethyl phosphonates using the microfluidic reactor

Hydroxymethyl phosphonates (HPs) are important organic chemical raw materials and intermediates. HPs are generally synthesized by phosphite esters and formaldehyde using the conventional organic synthesis device. It shows the disadvantages of strong heat-release and more by-products for the reaction, and high acid number (AN), low yield and low purity for the product. We have designed a microfluidic reactor to synthesize HPs that can overcome above mentioned disadvantages. During the microfluidic reaction process, a series of reaction conditions can be controlled precisely. According to adopt the optimal reaction conditions, five HPs were obtained with low AN (＜0.15 mg KOH/g), high yield (＞94%) and high purity (＞99%). The designed microfluidic reactor can reduce labor cost, save equipment area, and cut down the amount of wastewater. The synthesis process can also realize continuous production and scale-up production with no amplification effect.

Functionalized magnesium alloys obtained by superplastic forming process retain osteoinductive and antibacterial properties: An in-vitro study

ObjectivesThis study aimed to investigate the biocompatibility, osteogenic and antibacterial activity of biomedical devices based on Magnesium (Mg) Alloys manufactured by Superplastic Forming process (SPF) and subjected to Hydrothermal (HT) and Sol-Gel Treatment (Sol-Gel). MethodsMg-SPF devices subjected to Hydrothermal (Mg-SPF+HT) and Sol-Gel Treatment (Mg-SPF+Sol-Gel) were investigated. The biocompatibility of Mg-SPF+Sol-Gel and Mg-SPF+HT devices was observed by indirect and direct cytotoxicity assays, whereas the colonization of sample surfaces was assessed by confocal microscopy. qRT-PCR analysis and microbial growth curve analyses were employed to evaluate the osteogenic and antibacterial activity of both SPF-Mg treated devices, respectively. ResultsMg-SPF+HT and Mg-SPF+Sol-Gel showed a high degree of biocompatibility. Analysis of mRNA expression of osteogenic genes in cells cultured on Mg-treated devices revealed a significant upregulation of the expression levels of BMP2 and Runx-2. Furthermore, the bacterial growth in strains developed in contact with both the Mg-SPF+HT and Mg-SPF+Sol-Gel devices was lower than that observed in the control. SignificanceHydrothermal and Sol-Gel Treatments of Mg alloys obtained through the SPF process demonstrated bioactive, osteogenic and antibacterial activity, offering a promising alternative to conventional Mg-based devices. The obtained Mg-based materials may have the potential to enhance the tunability of temporary devices in maxillary reconstruction, eliminating the need for second surgeries, and ensuring a good bone reconstruction and a reduced implant failure rate due to bacterial infections.

Optimization of 150 nm GaN HEMT for Ku-band applications using field plate engineering

This work presents a systematic study to achieve the best result of having high breakdown voltage with high-frequency operation for a 150 nm GaN HEMT device (fabricated) using different field plate engineering techniques. The device breakdown voltage, cut-off frequency and maximum frequency should be high for high power and high frequency applications. The conventional device has a lower breakdown voltage but good cut-off and maximum frequency ranges. Field plate engineering has been done for breakdown improvement. However, the device's frequency operation is hampered by the typical source and gate field plate. As a result, an Air bridge source connected field plate and floating gate field plate architectures are explored and investigated. The best outcome is obtained with air bridge source connected field plate with VBOff = 100 V maintaining the cut-off frequency and maximum frequency at 29.8 GHz and 50.3 GHz respectively which is suitable for high power and high frequency applications.