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12 pages, 4092 KiB

Open AccessArticle

Identification of Effects of Parylene-C Coating on Electrospun Fibers

by Tae-Ha Song, Jeong Hwa Kim, Dong-Guk Kim, Jihyoung Roh and Young Hun Jeong

Fibers 2024, 12(8), 69; https://doi.org/10.3390/fib12080069 - 22 Aug 2024

Viewed by 1453

As various healthcare technologies such as regenerative medicine, precision medicine, and alternative approaches to animal testing develop, the interest in the use and application of nano- and microfibers is steadily increasing. In this study, the effect of parylene-C coating on electrospun fibers was investigated, and a pattern coating method was developed to expand the potential utilization of parylene-C-coated electrospun fibers. An SEM analysis demonstrated that parylene-C was successfully deposited on the electrospun fibers without any failure such as pinholes or air bubbles. Biocompatibility was investigated through cell tests, which indicated that the coated fibers were non-toxic and supported cell growth well. Tensile tests demonstrated a significant increase in the elastic modulus of the parylene-C-coated fibers, with it nearly quadrupling compared to the original PCL fibers, and the fracture strength almost doubled. At the same time, hydrophobicity was well maintained without any statistically significant changes. In particular, a non-adhesive magnet–metal masking was proposed in order to selectively coat the electrospun fibers with parylene-C with a specific pattern. Furthermore, it was presented that the magnet–metal mask-based coating electrospun nanofibers with parylene-C could be used in the fabrication of hybrid fibers composed of different diameters and materials. Full article

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12 pages, 2643 KiB

Open AccessArticle

Design of VGSOT-MTJ-Based Logic Locking for High-Speed Digital Circuits

by Divyanshu Divyanshu, Rajat Kumar, Danial Khan, Selma Amara and Yehia Massoud

Electronics 2022, 11(21), 3537; https://doi.org/10.3390/electronics11213537 - 30 Oct 2022

Cited by 5 | Viewed by 2663

Abstract

Emerging spintronics devices in recent research have received much interest in various fields. Their unique physical aspects are being explored to keep Moore’s law alive. Therefore, the hardware security aspects of system-on-a-chip (SoC) designs using spintronics devices becomes important. Magnetic tunnel junctions (MTJ) are a potential candidate in spintronics-based devices for beyond-CMOS applications. This work uses voltage-gated spin-orbit torque-assisted magnetic tunnel junction (VGSOT-MTJ) based on the Verilog-A behavioral model to design a possible logic-locking system for hardware security. Compared with the SOT MTJ, which uses a heavy metal strip below the MTJ stack, VGSOT-MTJ has an antiferromagnetic (AFM) strip that utilizes the voltage-controlled magnetic anisotropy (VCMA) effect to significantly reduce the

J_{S O T, c r i t i c a l}

. To design the logic-locking block, we performed a Monte Carlo analysis to account for the effect of process variation (PV) on critical MTJ parameters. Eye diagram tests and mask designing were performed, which included the effect of thermal noise and PV for high-speed digital circuit operations. Finally, transient performance was analyzed to demonstrate the VGSOT-MTJ’s ability to design logic-locking blocks from the circuit operation perspective. Full article

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18 pages, 10943 KiB

Open AccessArticle

Weld Seam Identification and Tracking of Inspection Robot Based on Deep Learning Network

by Jie Li, Beibei Li, Linjie Dong, Xingsong Wang and Mengqian Tian

Drones 2022, 6(8), 216; https://doi.org/10.3390/drones6080216 - 20 Aug 2022

Cited by 26 | Viewed by 5719

Abstract

The weld seams of large spherical tank equipment should be regularly inspected. Autonomous inspection robots can greatly enhance inspection efficiency and save costs. However, the accurate identification and tracking of weld seams by inspection robots remains a challenge. Based on the designed wall-climbing robot, an intelligent inspection robotic system based on deep learning is proposed to achieve the weld seam identification and tracking in this study. The inspection robot used mecanum wheels and permanent magnets to adsorb metal walls. In the weld seam identification, Mask R-CNN was used to segment the instance of weld seams. Through image processing combined with Hough transform, weld paths were extracted with a high accuracy. The robotic system efficiently completed the weld seam instance segmentation through training and learning with 2281 weld seam images. Experimental results indicated that the robotic system based on deep learning was faster and more accurate than previous methods, and the average time of identifying and calculating weld paths was about 180 ms, and the mask average precision (AP) was about 67.6%. The inspection robot could automatically track seam paths, and the maximum drift angle and offset distance were 3° and 10 mm, respectively. This intelligent weld seam identification system will greatly promote the application of inspection robots. Full article

(This article belongs to the Special Issue Intelligent Recognition and Detection for Unmanned Systems)

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6 pages, 3096 KiB

Open AccessArticle

A Magnetic Metal Hard Mask on Silicon Substrate for Direct Patterning Ultra-High-Resolution OLED Displays

by Lin Chen, Xiuxia Wang, Yu Wei and Chenggang Zhou

Micromachines 2022, 13(7), 997; https://doi.org/10.3390/mi13070997 - 25 Jun 2022

Cited by 7 | Viewed by 4149

Abstract

With the development of virtual reality/augmented reality (VR/AR) display devices, the conventional fine metal mask is limited by the wet etch process, which no longer meets the demand for high pixels per inch (PPI) displays. We deposited a layer of magnetic metal on the silicon substrate by physical vapor deposition (PVD), and then developed a 2-inch, 3175 PPI magnetic metal hard mask on silicon substrate (MMS) through deep silicon etching and other micro-nano processing for patterning Organic Light-Emitting Diodes (OLED) displays, which can achieve smaller pixel size and higher PPI. MMS can not only solve the bottleneck problem of the traditional invar alloy shadow mask with low PPI, but also reduce the bending caused by the deformation of the silicon-based mask due to gravity, so that it achieves high PPI and higher uniformity in OLED displays. Full article

(This article belongs to the Special Issue Selected Papers from the 23rd Annual Conference and 12th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2021))

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16 pages, 2609 KiB

Open AccessArticle

Synthesis, Crystal Structures, and Spectroscopic Properties of Novel Gadolinium and Erbium Triphenylsiloxide Coordination Entities

by Patrycja Wytrych, Józef Utko, Julia Kłak, Maciej Ptak, Mariusz Stefanski, Tadeusz Lis, Jolanta Ejfler and Łukasz John

Molecules 2022, 27(1), 147; https://doi.org/10.3390/molecules27010147 - 27 Dec 2021

Cited by 4 | Viewed by 2942

Abstract

In alkali metal and lanthanide coordination chemistry, triphenylsiloxides seem to be unduly underappreciated ligands. This is as surprising as that such substituents play a crucial role, among others, in stabilizing rare oxidation states of lanthanide ions, taking a part of intramolecular and molecular interactions stabilizing metal-oxygen cores and many others. This paper reports the synthesis and characterization of new lithium [Li₄(OSiPh₃)₄(THF)₂] (1), and sodium [Na₄(OSiPh₃)₄] (2) species, which were later used in obtaining novel gadolinium [Gd(OSiPh₃)₃(THF)₃]·THF (3), and erbium [Er(OSiPh₃)₃(THF)₃]·THF (4) configuration, it can result in res were determined for all 1–4 compounds, and in addition, IR, Raman, absorption spectroscopy studies were conducted for 3 and 4 lanthanide compounds. Furthermore, direct current (dc) variable-temperature magnetic susceptibility measurements on polycrystalline samples of 3 and 4 were carried out in the temperature range 1.8–300 K. The 3 shows behavior characteristics for the paramagnetism of the Gd³⁺ ion. In contrast, the magnetic properties of 4 are dominated by the crystal field effect on the Er³⁺ ion, masking the magnetic interaction between magnetic centers of neighboring molecules. Full article

(This article belongs to the Section Inorganic Chemistry)

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