Skip to main content
  • Home
  • Contact Us
  • ShinMaywa Global Network
  • ShinMaywa Global Site
  • 日本語
  • English
Text Size
  • Small
  • Medium
  • Large
  • Sitemap

Investigation of Insertion Phenomena with Needles Treated by Plasma Etching

Omar Alghurair Open Link in New Window ・ Alexey Remnev ・ Keisuke Nagato Open Link in New WindowShota Ikeshima Open Link in New WindowOno Yasunori Open Link in New WindowKensuke Uemura Open Link in New WindowMasayuki Nakao Open Link in New Window
ABSTRACT: Pain during injection of a medical needle is greatly influenced by the surface roughness and geometry of its cutting edges. An ion- plasma sputtering treatment is a promising candidate as a clean and precise polishing method for the painless needles. In this paper, the mechanism of the reduction of inserting force of the plasma-treated needles is investigated by microscopically observing artificial skins and needles during insertion. It was found that the time distribution of insertion force was influenced by the roughness at the cutting edges. Plasma-treated needles resulted in force reduction by approximately half in comparison of untreated ones. Furthermore, the microscopic observation found that the sharp dropping of force was occurring at the corners between cutting faces. Using the plasma-treated needle, the sharp dropping was significantly decreased. The plasma-etching treatment will lead to a clean finishing process for painless medical needles.
12/2013; 5:53?56. DOI:10.1016/j.procir.2013.01.010

Ion trajectories calculation for negatively biased needle cathode in volume discharge plasma

A G Remnev ・ K Uemura Open Link in New WindowA V Kozyrev Open Link in New WindowV V Lopatin Open Link in New Window
ABSTRACT: Ion trajectories were simulated for the case of multi-needle negatively biased electrode immerged into the volume type plasma. The model was simplified to the 2d case with planar plasma boundary. The electrical field distribution was calculated with the FEA method. Resulting piece wise function was then used to predict ion trajectories emitted from the plasma sheath boundary. Series of the ion trajectories were simulated for different plasma and accelerating gap parameters using single particle analysis. Distribution of the ion current density along the needle surface and angles of the ion incidence were obtained from the simulation. Experimental and theoretical etching profiles are consistent.
Journal of Physics Conference Series 11/2014; 552:012009. DOI:10.1088/1742-6596/552/1/012009

Effect of reactive gas additives on surface morphology evolution of stainless steel substrate undergoing low energy Ar ion bombardment

A.G. Remnev ・ K. Nagato Open Link in New WindowK Uemura Open Link in New Window
ABSTRACT: In many cases surface ion bombardment results in roughening of metal's and alloy's surfaces. In the present study, a phenomenon of surface roughening inhibition during the ion bombardment is presented. The phenomenon occurred during the plasma extracted ion sputter etching at normal incidence with 400 eV positive ions, when 1% of dried air was added into the plasma forming Ar gas. Two 18%Cr?10%Ni mechanically polished to about 2 nm average roughness (Ra) stainless steel test pieces were sputter etched with and without the air additive. The roughening was inhibited to Ra ? 4 nm, which was about 9.5 times lower than that of the sputtered without air additive (Ra ? 38 nm). The phenomenon is discussed in terms of chemisorption of active plasma species introduced by the air additive and competing roughening/smoothening mechanisms.
Vacuum 09/2015; 119. DOI:10.1016/j.vacuum.2015.05.024