The Biological Safety of Stainless Steel Needles Used in Warm-needling

Warm-needling (also called thermo-acupuncture) is a combination of acupuncture and moxibustion. Due to the intense heat involved, there have been concerns over the biological safety of the acuneedles used in the treatment. This paper reports two phases of a safety test. For a preliminary test, we compared the temperature change patterns of stainless steel (SS304) needles and traditional gold alloy needles, which have been increasingly replaced by the former. To verify the effects of the presence of coating materials, the main test involved three different kinds of SS304: silicone-coated, salicylic acid-coated and non-coated needles. Each group of needles was tested for pH level, heavy metals and UV absorbance spectrum along with biological tests on the cytotoxicity and hemolysis of the needle. All the tests on the extractants from the needles were negative. In the biological tests, each test result showed a significant difference from the positive control samples, while no significant difference was observed compared with the negative control samples. In the hemolysis tests, all samples satisfied the Korean Government Standards. All the results suggest that SS304 needles are biologically safe to be used in warm-needling, though they can be improved to perform as well as the gold alloy needles in terms of temperature fluctuations

Effect of Diamond like Carbon Coating Thickness on Stainless Steel Substrate

Diamond like carbon coatings have excellent wear properties with high hardness. The hardness and adhesion properties vary with sp3/sp2 ratio and coating thickness. In this research, effect of coating thickness on stainless steel substrate has studied. Diamond like carbon coatings of 300nm, 500nm, and 650nm has deposited using Filter Cathodic Vacuum Arc System with Magnetron sputtered Chromium interlayer. The characterization includes, Field Emission Electron Microscopy, Raman spectroscopy, Tribology and Adhesion strength evaluation. It was concluded that, surface finish decreased with increase in coating thickness. Maximum ID/IG of 0.84 was obtained for 30nm diamond like carbon coated stainless steel. The minimum average friction coefficient of 0.115 was obtained for 500nm coating. Moreover, it was observed that, friction coefficient decrease with increase in coating thickness in initial phases, after certain time it increase directly proportional to thickness. For adhesion strength, LC1 was found good for 650nm and LC2 for 500nm respectively