Integrating Electronics to Textiles by Ultrasonic Welding for Cable-Driven Applications for Smart Textiles

The connection between flexible textiles and stiff electronic components has always been structurally weak and a limiting factor in the establishment of smart textiles in our everyday life. This paper focuses on the formation of reliable connections between conductive textiles and conventional litz wires using ultrasonic welding. The paper offers a promising approach to solving this problem. The electrical and mechanical performance of the samples were investigated after 15 and 30 wash-and-dry cycles in a laundry machine. Here the contact resistances and their peeling strength were measured. Furthermore, their connection properties were analysed in microsections. The resistance of the joints increased more than 300%, because the silver-coated wires suffered under the laundry cycles. Meanwhile, the mechanical strength during the peeling test decreased by only about 20% after 15 cycles and remained the same after 30 cycles. The good results obtained in this study suggest that ultrasonic welding offers a useful approach to the connection of textile electronics to conductive wires and to the manufacture of smart textiles.

Evaluation of the surface properties of modified Ni-Ti arch wires

Aim: Materials used in orthodontic treatment can cause corrosion and metal ion release to the mouth. This study was aimed to examine the changes in the friction coefficients and corrosion resistance of the modified Ni-Ti arch wires. Methodology: Our sample consisted of 16 Ni-Ti arch wires (0.016 × 0.022 inches). Coating bathes involving Ni-Ti, Ni-Ti-Mo, and Ni-Ti-Cr were prepared for arch wires coating. New surfaces were analyzed by SEM, and the crystallographic structure was determined by X-rays. The friction coefficient of the coated wires was determined by nanoindentation. Artificial saliva was prepared as a corrosive condition. Impedance measurements were performed with an electrochemical analyzer. The AC impedance spectroscopy measurements were performed after four hours, seven, 15, 30, 45, and 60 days. Results: All groups were more resistant than the control group (-447 mV) [group 1 (-388 mV), group 2 (-328 mV), group 3 (-327 mV), group 4 (-427 mV), group 5 (-395 mV), group 6 (-366 mV), and group 7 (-380 mV)]. Friction coefficients of group 5 (0.252) and group 6 (0.265) were observed to be lower than those of the control group (0.288). Conclusion: In the results of our study, it was shown that the surface properties of Ni-Ti wires could be electrochemically improved. The coated wires (group 5 and group 6) had a remarkable corrosion resistance and reduced friction. The protocols that we used should help provide better-quality surfaces. How to cite this article: Özyılmaz AT, Bilgiç Zortuk F, Yılmaz H. Evaluation of the surface properties of modified ni-ti arch wires. Int Dent Res 2021;11(Suppl.1):167-176. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.25 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Effect of electrode material on removal efficiency regarding single discharges in wire EDM

For the precise machining of demanding materials, wire electrical discharge machining (WEDM) is a flexible and often irreplaceable manufacturing process. In order to enhance productivity as the main focus of the wire EDM process, the advancement of the fundamental procedural understanding is of decisive importance. In order to be able to energetically evaluate the removal process, the individual energetic contributors of the process hence the individual discharges need to be understood in terms of their contribution to material removal. In this paper, an experimental setup is presented, which permits the generation of individual discharges on a modern industrial wire EDM machine tool. For three different wire electrodes, the correlation of the discharge energy and the individual removal volume is quantitatively described, showing that coated wires achieve a significantly higher energy-specific removal. Furthermore the removal efficiency is defined as a key figure to transfer the findings to the continuous process and compare theoretical and effective removal rate.

Revascularization of Chronic Iliac Vein Occlusion Using Balloon-Assisted Transseptal Needle Puncture Technique

Objectives To evaluate the utility of a transseptal needle for balloon-assisted sharp recanalization of chronically occluded central venous structures. Background Chronically occluded central veins are not an uncommon problem, which may arise due to a plethora of reasons. Traditionally, wire and catheter techniques are often used first in an attempt to reestablish flow. When these methods fail, more aggressive techniques are employed, such as sharp recanalization using the back end of wires, Teflon-coated wires, or Rosch–Uchida or Colapinto needles. However, utilization of transseptal needles, traditionally reserved for cardiac procedures, has rarely been described. Methods Transseptal needle was utilized for balloon-assisted sharp recanalization after traditional wire and catheter techniques failed in revascularization of chronically occluded iliac veins. Results Transseptal needle was utilized successfully in two cases in revascularization of chronically occluded central veins. Conclusion Transseptal needle is a viable tool to add to the interventional radiologists’ armamentarium in reestablishing flow in chronically occluded central veins.

Comparison of Cell Viability and Chemical Composition of Six Latest Generation Orthodontic Wires

Orthodontic wires are made of alloys containing different metals, including nickel. It is important to evaluate their biocompatibility prior to use, owing to their long-term use in patients. This in vitro study compared the cytotoxicity and chemical composition of six latest orthodontic wires: Fantasia®, Tanzo®, FLI®, NT3®, DuoForce®, and Gummetal®. The before-use group consisted of wires that were not used in the mouth, and the after-use group consisted of wires that were used in the mouth for two months. The wires were placed in contact with human gingival fibroblasts (HGF) for 72 h, and cytotoxicity was determined using the resazurin test. The chemical composition and surface characterisation were evaluated by spectrometry and scanning electron microscopy. The groups were compared using ANOVA and Kruskal–Wallis test. Only the FLI® wires produced a 36% reduction in HGF viability ( p < 0.05 ) and presented greater irregularities and loss of polymer structure. After-use wires showed a significant reduction in the percentage of nickel and the appearance of new elements (oxygen and carbon). Therefore, it can be concluded that no toxic ion release was noticed in this study. Rhodium-coated wires were more stable than PTFE-coated wires, and only the FLI® wires showed a slight cytotoxic effect.

Attractiveness of different esthetic orthodontic wires

ABSTRACT Objective: The aim of this study was to evaluate the attractiveness of different types of esthetic orthodontic wires by laypeople and dentists. Methods: Five different types of orthodontic wires were evaluated: three esthetic wires (Teflon-coated, epoxy resin-coated and rhodium-coated wires), and two metallic wires (stainless steel and NiTi), as control. Monocrystalline ceramic brackets were installed in the maxillary arch of a patient presenting good dental alignment. The five evaluated wires were attached to the orthodontic appliance with an esthetic silicone elastic and photographed. The photographs were evaluated by 163 individuals, 110 dentists and 53 laypeople. The data were statistically evaluated by two-way ANOVA and one-way ANOVA, followed by Tukey tests. Results: There was a statistically significant difference in the attractiveness among the wires evaluated; the most esthetic was the rhodium-coated wire, followed by the epoxy resin-coated wire and, finally, the Teflon-coated wire, with no significant difference from the stainless steel and NiTi control archwires. There was no significant difference between the groups of evaluators. Conclusion: The most attractive was the rhodium-coated wire, followed by the epoxy resin-coated wire and, finally, the least attractive wire was the Teflon-coated wire, without statistically significant difference to the stainless steel and NiTi wires, used as control.