6 reported on a variety of hard coatings for stainless steel surgical scalpels, including diamond-like carbon (DLC), tungsten carbide/carbon (WC/C) and titanium nitride (TiN). Numerous coatings have been proposed to overcome this issue. Furthermore, it is not economically feasible to use disposable stainless steel scalpels, which lose their sharpness rapidly and thus necessitate the use of multiple devices to perform a single surgical incision.
The application of a dermatome to cut soft tissue of skin can produce tearing trauma, which slows wound healing and increases the pain associated with surgery 5. These effects can be seen in the irregular, wavy surfaces at edge-tip of surgical blades under magnification 4.
The polycrystalline structure of martensitic stainless steel includes grains and grain boundaries, which unfortunately serve as crack initiation sites, eventually leading to localized fracturing on the blade. Wear resistance is particularly important when making long incisions, often reaching 30 cm or longer. Surgical scalpels and blades of martensitic stainless steel are standard tools in soft tissue surgery 3. It is for this reason that most surgical blades are composed primarily of martensitic stainless steel (AISI 420), which has high hardness as well as good resistance to wear and mechanical deformation at the tip of blade. Blades of higher sharpness, strength, and durability tend to be more accurate in the removal of damaged skin or the harvesting of new grafts. One key aspect of reconstructive and plastic surgery relates the process of preparing the corresponding donor sites and the actual process of splitting the skin. Split-thickness grafts are used to cover large areas, and feature a low rejection rate 2. Skin grafts can be categorized as split-thickness and full-thickness.
This approach to wound coverage has greatly advanced since that time, and is now considered a safe, reliable, and practical procedure. Reverdin succeeded in applying epidermal grafts to a granulating wound 1. This technique is commonly employed when skin is damaged due to extensive trauma, such as burns. Skin grafts involve the removal of skin from one area of the body for transplantation in another area of the body. This is a clear demonstration of the efficacy of TFMG surface coatings in preserving the cutting quality of surgical instruments. By Day 7, the wounds produced using TFMG-coated blades were noticeably smaller than those produced using uncoated blades, and these effects were particularly evident in hairy samples.
In the presence of hair, the surface roughness of uncoated blades increased by approximately ~108%, whereas the surface roughness of TFMG-coated blades increases by only ~23%. When tested repeatedly on hairless skin, the surface roughness of uncoated blades increased by approximately 70%, whereas the surface roughness of TFMG-coated blades increases by only 8.6%. The performance of Z-TFMG and F-TFMG was also evaluated in split-thickness skin graft surgery using dermatome blades aimed at elucidating the influence of TFMG coatings on the healing of surgical incisions. These results demonstrate the efficacy of the TFMG coating in terms of low friction, non-stick performance, and substrate adhesion. The Z-TFMG presented no indications of delamination after being used 30 times for cutting however, the Teflon coating proved highly susceptible to peeling and the bare blade was affected by surface staining. We also found that the Teflon coating reduced the cutting forces of an uncoated microtome blade by ~80%, whereas the proposed Z-TFMG achieved a ~51% reduction. Comparisons were conducted with bare blades and those with a Teflon coating (a low-friction material commonly used for the coating of microtome blades). In oil-repellency/sliding tests on kitchen blades, the sliding angle and friction forces were as follows: bare blades (31.6°) and (35 µN), Ti-coated blades (20.3°) and (23.7 µN), and Z-TFMG coated blades (16.2°) and (19.2 µN). In this study, we sought to enhance the cutting properties of the various blades by coating them with Zr- and Fe-based thin film metallic glasses (TFMGs) to a thickness of 234–255 nm via sputter deposition.