Evaluation of Stress on Acupuncture with Nano-Etched and Diamond-Like Carbon (DLC) Coating Surface Modifications

2022 ◽  
Vol 12 (3) ◽  
pp. 489-493
Author(s):  
Yung-Sheng Yen ◽  
Han-Yi Cheng ◽  
Hung-Ta Lin

The aim of the present study was to investigate the effect of nano-etched surface and diamond-like carbon (DLC) surface acupuncture needles on human pain perception, by finite element method (FEM). Skin models were reconstructed by 3D computer programs. The stress is an important role in acupuncture needle applications for clinical treatment. Many studies have investigated finite element researches for acupuncture; however, few have evaluated a model for acupuncture with and without\ modified surface. The results revealed that abnormal focusing stress was found when acupuncture with nano-etched surface. Moreover, the unbalance stress was found on the top of the skin model in the nano-etched group, the highest stress also appeared in the top region. Acupuncture with nano-etched surface would be an effective means for stimulating skin. These results indicate subtle but significant effects of acupuncture stimulation with nano-etched surface needles, compared to acupuncture with untreated needles in healthy participants.

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 376
Author(s):  
Mao Kaneko ◽  
Masanori Hiratsuka ◽  
Ali Alanazi ◽  
Hideki Nakamori ◽  
Kazushige Namiki ◽  
...  

We evaluated the adhesion, friction characteristics, durability against bodily acids, sterilization, cleaning, and anti-reflection performance of diamond-like carbon (DLC) coatings formed as a surface treatment of intracorporeal medical devices. The major coefficients of friction during intubation in a living body in all environments were lower with DLC coatings than with black chrome plating. DLC demonstrated an adhesion of approximately 24 N, which is eight times stronger than that of black chrome plating. DLC-coated samples also showed significant stability without being damaged during acid immersion and high-pressure steam sterilization, as suggested by the results of durability tests. In addition, the coatings remained unpeeled in a usage environment, and there was no change in the anti-reflection performance of the DLC coatings. In summary, DLC coatings are useful for improving intracorporeal device surfaces and extending the lives of medical devices.


1991 ◽  
Vol 239 ◽  
Author(s):  
Fred M. Kimock ◽  
Alex J. Hsieh ◽  
Peter G. Dehmer ◽  
Pearl W. Yip

ABSTRACTWe report on a recently commercialized Diamond-Like Carbon (DLC) coating that has been deposited on polycarbonate at near room temperature, via a unique ion beam system. Aspects of high speed impact behavior, chemical resistance, abrasion resistance, and thermal stability of the coating are examined. Results of scanning electron microscopy studies indicate that adhesion of the DLC coating is very good; no delamination of the coating was found on ballistically tested specimens. The well-bonded DLC coating did not cause the impact performance of polycarbonate to become brittle. Chemical exposure test results show that the DLC coating is capable of protecting polycarbonate from chemical attack by aggressive organic liquids. These ion beam deposited DLC coatings have considerable potential as protective coatings for optical systems.


2006 ◽  
Vol 129 (1) ◽  
pp. 58-65 ◽  
Author(s):  
B. Scott Kessler ◽  
A. Sherif El-Gizawy ◽  
Douglas E. Smith

The accuracy of a finite element model for design and analysis of a metal forging operation is limited by the incorporated material model’s ability to predict deformation behavior over a wide range of operating conditions. Current rheological models prove deficient in several respects due to the difficulty in establishing complicated relations between many parameters. More recently, artificial neural networks (ANN) have been suggested as an effective means to overcome these difficulties. To this end, a robust ANN with the ability to determine flow stresses based on strain, strain rate, and temperature is developed and linked with finite element code. Comparisons of this novel method with conventional means are carried out to demonstrate the advantages of this approach.


2001 ◽  
Author(s):  
Ben Ting ◽  
Vincent P. Manno

Abstract For semiconductor lasers, fiber and optical source alignment is crucial for maintaining high optical transfer efficiency. Traditional optoelectronic manufacturing, production of butterfly packages for example, involves laser welding of fiber mountings followed by a tedious realignment procedure to reverse thermally-induced distortions. An alternate technique, laser hammering, entails manipulation of the fiber to light alignment through deformation of the fiber housing with high precision laser beams. A detailed understanding of the material and mechanical behavior, characteristics, and dynamic response is vital to successfully apply an efficient controller that can choose an optimal weld pattern based on a light to fiber misalignment. Modeling provides an effective means to determine an optimal fiber alignment control technique. Modeling is difficult due to the dynamic thermal-mechanical coupling of these processes. This paper presents the preliminary results of a series of parametric studies regarding thermal-mechanical coupling models employed in finite element analysis in order to assess the behavior and dynamic response of representative materials and geometries under various boundary conditions. Fiber ferrule and ferrule housing dimensions affect resistance to bending and torsion, which in turn governs the magnitude of the displacement field. The models are then applied to geometries typical of alignment fixtures used in laser diode packages. The effects of laser energy deposition location and resolution as well as assumed boundary and initial conditions are also discussed. Convection and the small variations in ferule geometry do not have a strong effect on the overall response.


2006 ◽  
Vol 6 (11) ◽  
pp. 3619-3623
Author(s):  
Eung-Sug Lee ◽  
Jun-Ho Jeong ◽  
Ki-Don Kim ◽  
Young-Suk Sim ◽  
Dae-Geun Choi ◽  
...  

Two-dimensional (2-D) and three-dimensional (3-D) diamond-like carbon (DLC) stamps for ultraviolet nanoimprint lithography were fabricated with two methods: namely, a DLC coating process, followed by focused ion beam lithography; and two-photon polymerization patterning, followed by nanoscale-thick DLC coating. We used focused ion beam lithography to fabricate 70 nm deep lines with a width of 100 nm, as well as 70 nm deep lines with a width of 150 nm, on 100 nm thick DLC layers coated on quartz substrates. We also used two-photon polymerization patterning and a DLC coating process to successfully fabricate 200 nm wide lines, as well as 3-D rings with a diameter of 1.35 μm and a height of 1.97 μm, and a 3-D cone with a bottom diameter of 2.88 μm and a height of 1.97 μm. The wafers were successfully printed on an UV-NIL using the DLC stamps without an anti-adhesive layer. The correlation between the dimensions of the stamp's features and the corresponding imprinted features was excellent.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5077
Author(s):  
Magdalena Antonowicz ◽  
Roksana Kurpanik ◽  
Witold Walke ◽  
Marcin Basiaga ◽  
Jozef Sondor ◽  
...  

Despite high interest in the issues of hemocompatibility of titanium implants, particularly those made of the Ti-13Nb-13Zr alloy, the applied methods of surface modification still do not always guarantee the physicochemical properties required for their safe operation. The factors that reduce the efficiency of the application of titanium alloys in the treatment of conditions of the cardiovascular system include blood coagulation and fibrous proliferation within the vessel’s internal walls. They result from their surfaces’ physicochemical properties not being fully adapted to the specifics of the circulatory system. Until now, the generation and development mechanics of these adverse processes are not fully known. Thus, the fundamental problem in this work is to determine the correlation between the physicochemical properties of the diamond like carbon (DLC) coating (shaped by the technological conditions of the process) applied onto the Ti-13Nb-13Zr alloy designed for contact with blood and its hemocompatibility. In the paper, microscopic metallographic, surface roughness, wettability, free surface energy, hardness, coating adhesion to the substrate, impendence, and potentiodynamic studies in artificial plasma were carried out. The surface layer with the DLC coating ensures the required surface roughness and hydrophobic character and sufficient pitting corrosion resistance in artificial plasma. On the other hand, the proposed CrN interlayer results in better adhesion of the coating to the Ti-13Nb-13Zr alloy. This type of coating is an alternative to the modification of titanium alloy surfaces using various elements to improve the blood environment’s hemocompatibility.


2001 ◽  
Vol 52 (12) ◽  
pp. 878-882 ◽  
Author(s):  
Shojiro MIYAKE ◽  
Tadashi SAITOH ◽  
Shuichi WATANABE ◽  
Eiichi HAYASHI ◽  
Takashi NAKAMARU

Author(s):  
B. Scott Kessler ◽  
A. Sherif El-Gizawy

The accuracy of a finite element model for design and analysis of a metal forging operation is limited by the incorporated material model’s ability to predict deformation behavior over a wide range of operating conditions. Current rheological models prove deficient in several respects due to the difficulty in establishing complicated relations between many parameters. More recently, artificial neural networks (ANN) have been suggested as an effective means to overcome these difficulties. In the present work, a previously developed ANN with the ability to determine flow stresses based on strain, strain rate, and temperature is incorporated with finite element code. Utilizing this linked approach, a preliminary model for forging an aluminum wheel is developed. This novel method, along with a conventional approach, is then measured against the forging process as it is currently performed in actual production.


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