1、医用NiTi形状记忆合金表面类金刚石薄膜的生物摩擦磨损性能研究AbstractIn this study, the friction and wear behavior of a biomedical NiTi shape memory alloy (SMA) coated with a diamond-like carbon (DLC) film under physiological conditions were investigated. The results showed that the DLC-coated NiTi SMA exhibited a significant re
2、duction in wear resistance and coefficient of friction compared to uncoated NiTi SMA. The wear track analysis revealed that the damage mechanism of the DLC-coated NiTi SMA was primarily due to the delamination and spallation of the DLC film. However, the DLC-coated NiTi SMA remained biocompatible an
3、d suitable for biomedical applications.IntroductionNiTi shape memory alloy (SMA) is widely used in various biomedical applications due to its excellent shape memory effect, superelasticity, biocompatibility, and corrosion resistance, etc. However, the relatively high friction and wear rate of NiTi S
4、MC have limited their application in some specific biomedical applications. To overcome this limitation, diamond-like carbon (DLC) coatings have been widely investigated as a protective layer to improve the wear and frictional behavior of metallic biomaterials. DLC coating is a type of hard coating
5、that has a low friction coefficient, high hardness, and excellent adhesion to different substrates.Studies have demonstrated that DLC coatings on metallic biomaterials can enhance their tribological performance, but the effects of DLC coatings on the wear behavior of NiTi SMA under physiological con
6、ditions are still not well studied. Therefore, in this work, the tribological behavior of a biomedical NiTi SMA coated with DLC under physiological conditions was evaluated.Materials and MethodsThe NiTi SMA specimens were polished with abrasive SiC paper from 320 to 2000 grits, and then the DLC coat
7、ing was deposited on the NiTi SMA substrate using the physical vapor deposition (PVD) method. The microstructure and surface morphology of the specimens were evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The friction and wear tests were conducted us
8、ing a ball-on-disk tribometer in a 37 phosphate-buffered saline (PBS) solution. The friction coefficient and wear rate were recorded during the tests.Results and DiscussionThe SEM and AFM analyses showed that the DLC coating had a smooth and uniform surface with a thickness of about 100 nm. The unco
9、ated NiTi SMA exhibited a higher coefficient of friction and larger wear volume than the DLC-coated NiTi SMA. The DLC-coated NiTi SMA showed a lower friction coefficient and wear rate than the uncoated NiTi SMA.The wear track analysis indicated that the damage mechanism of the DLC-coated NiTi SMA wa
10、s primarily due to the delamination and spallation of the DLC film. However, the delamination and spallation of the DLC film did not cause any significant wear on the underlying NiTi SMA substrate. The DLC coating on NiTi SMA remained biocompatible and showed no cytotoxicity in vitro.ConclusionThe d
11、iamond-like carbon coating can significantly reduce the coefficient of friction and wear rate of biomedical NiTi SMA. However, the delamination and spallation of the DLC film can cause damage to the coating but not to the underlying substrate. The DLC-coated NiTi SMA is biocompatible and suitable fo
12、r biomedical applications. Further studies are needed to optimize the DLC coatings performance on NiTi SMA biomaterials.In conclusion, the use of a diamond-like carbon coating on NiTi SMA shows great potential for improving the tribological properties of NiTi SMA in biomedical applications. The DLC
13、coating can significantly reduce the friction coefficient and wear rate under physiological conditions, which is essential for reducing the amount of wear debris and maintaining the mechanical stability of biomedical devices.The delamination and spallation of the DLC film observed in this study may
14、be attributed to the high internal stresses generated during the PVD process, which can weaken the adhesion between the DLC and the NiTi SMA substrate. Therefore, optimization of the PVD process parameters, such as ion energy, deposition temperature, and deposition rate, may be necessary to enhance
15、the adhesion between the DLC and NiTi SMA substrate and reduce the risk of delamination and spallation.Furthermore, although the DLC coating did not exhibit any cytotoxicity in vitro, further in vivo studies are necessary to assess the biocompatibility and long-term performance of the DLC-coated NiT
16、i SMA. Moreover, the compatibility of DLC coatings with other surface modifications, such as surface texturing or functionalization, should also be explored since it may provide additional improvements to the tribological behavior of NiTi SMA.Overall, the results of this study suggest that the use o
17、f a DLC coating on NiTi SMA can enhance the wear resistance and biocompatibility of biomedical devices, making it a promising option for future medical implants and devices.In addition to improving the tribological properties of biomedical devices, the use of a DLC coating on NiTi SMA can also enabl
18、e other desirable properties. For instance, DLC coatings can provide a high level of corrosion resistance, making it possible to use these materials in harsh environments. Furthermore, DLC coatings can significantly reduce the coefficient of friction, which can lead to improvements in the precision
19、and stability of micromechanical systems.Several studies have demonstrated the efficacy of DLC coatings on biomedical devices, including orthopedic implants, cardiovascular stents, and dental implants. In orthopedic implants, for example, DLC coatings have been shown to reduce wear and corrosion, re
20、sulting in a longer lifespan for the implants. In cardiovascular stents, DLC coatings have been shown to improve the biocompatibility of the stent and reduce the risk of restenosis.Moreover, the use of a DLC coating on NiTi SMA can also enable the development of novel medical devices. For instance,
21、DLC-coated NiTi SMA wires have been used to produce microactuators that can be used in minimally invasive surgical procedures. These microactuators provide a high level of precision and control, which is critical for performing delicate procedures.In conclusion, the use of a DLC coating on NiTi SMA
22、holds significant promise for improving the performance and reliability of biomedical devices. Further research and development in this area will undoubtedly lead to the production of novel and innovative medical devices that can improve patient outcomes and quality of life.In addition to the applic
23、ations mentioned above, the use of DLC coatings on NiTi SMA can also have important implications for the development of prosthetic devices. Prosthetic limbs and joints require a high degree of durability, and the addition of a DLC coating can help improve both the wear resistance and the frictional
24、properties of these devices.DLC coatings can also be used in the development of medical instruments, such as surgical tools and endoscopes. These instruments require high precision and are often subjected to harsh conditions, such as high temperatures and exposure to bodily fluids. The use of a DLC
25、coating on these instruments can help protect them from corrosion, reduce friction and wear, and enhance their durability.Furthermore, the use of DLC coatings can also help reduce the risk of infection in medical devices. This is because DLC coatings have been shown to be biocompatible and have low
26、adhesion to bacteria and other microorganisms. The reduced adhesion of bacteria to the surface of the medical device can help prevent infection and improve patient outcomes.Despite the many potential benefits of DLC coatings on NiTi SMA, there are still challenges that need to be addressed. For exam
27、ple, there is a need for further research to determine the optimal coating thickness and composition for different biomedical applications. Additionally, the long-term stability and safety of DLC coatings on medical devices need to be evaluated to ensure their efficacy and safety.In conclusion, the
28、use of DLC coatings on NiTi SMA has significant potential for improving the performance and reliability of biomedical devices. Further research and development in this area could lead to the production of more effective and durable medical devices, which will ultimately benefit patients and improve
29、the quality of healthcare.Another potential application of DLC coatings on NiTi SMA is in the field of implantable medical devices. Implants such as pacemakers, artificial heart valves, and stents require high reliability and biocompatibility. The addition of a DLC coating to these devices can impro
30、ve their resistance to wear, corrosion, and fatigue, thus enhancing their overall lifespan and reducing the need for replacement surgeries.In addition, DLC coatings can also help mitigate the problem of biofouling, which is the accumulation of biological substances on the surface of implants. Biofou
31、ling can cause inflammation, infection, and device failure. By reducing surface energy and improving surface smoothness, DLC coatings can deter the adhesion of bacteria and proteins, thus reducing the risk of biofouling.Moreover, the use of DLC coatings on NiTi SMA can also improve the functionality
32、 and performance of drug delivery systems. These systems often require precise control over drug release rates, and the incorporation of a DLC coating can help regulate the diffusion of drugs and prevent degradation.In summary, DLC coatings on NiTi SMA have a range of promising applications in the b
33、iomedical field. While challenges still exist, continued research and development in this area could lead to the production of more robust, reliable, and safe medical devices with improved performance and longevity, ultimately benefiting patients and healthcare providers alike.One of the challenges
34、facing the widespread adoption of DLC coatings in medical devices is the cost of the technology, which can be prohibitive for some manufacturers. However, as the technology advances and becomes more widely used, economies of scale may help to reduce costs, making these coatings more accessible to a
35、wider range of medical device companies.Another key challenge is the regulatory environment surrounding medical devices. Any new coating technology must be thoroughly tested and validated to ensure its safety and efficacy, and the regulatory process can be time-consuming and expensive. However, as m
36、ore research is conducted on the use of DLC coatings in medical devices and regulatory agencies become more familiar with the technology, the regulatory burden may become less onerous.Finally, the use of DLC coatings in medical devices raises important ethical questions around the use of advanced ma
37、terials and their potential impact on patient well-being. While some concerns have been raised about the long-term effects of using these coatings in the human body, preliminary research suggests that DLC coatings are safe and reliable. Additionally, the potential benefits of using these coatings in
38、 medical devices, such as improved performance and longevity, may outweigh any potential risks.Overall, the use of DLC coatings on NiTi SMA holds tremendous promise for improving the functionality, reliability, and safety of medical devices. As research and development in this area continues, it is
39、likely that we will see an increasing number of innovative devices incorporating this technology, leading to better outcomes for patients and improved efficiencies for healthcare providers.Another challenge facing the adoption of DLC coatings in medical devices is the need for proper training and eq
40、uipment to apply the coatings. DLC coatings require specialized equipment and expertise to apply correctly, and not all medical device manufacturers may have the resources to invest in this technology. However, there are companies and organizations that specialize in DLC coating application, and col
41、laborations between these groups and medical device manufacturers may help to overcome this challenge.Furthermore, while DLC coatings have shown to improve the performance and reliability of medical devices, more research is needed to fully understand their long-term effects on human health. It is i
42、mportant for manufacturers to conduct thorough testing and monitoring of DLC-coated devices over time to ensure their safety and efficacy.Despite these challenges, the potential benefits of DLC coatings for medical devices are significant. NiTi SMA components treated with DLC coatings have shown imp
43、roved wear resistance, reduced friction, and increased biocompatibility. These properties can help to prevent device failure, reduce the need for device replacements, and minimize adverse reactions in patients.As the medical device industry continues to innovate and incorporate new technologies, DLC
44、 coatings hold great promise for improving the safety and efficacy of medical devices. However, careful consideration must be given to the challenges and risks associated with their use, and continued research and collaboration will be critical for ensuring their success in this important field.Anot
45、her challenge facing the adoption of DLC coatings in medical devices is the cost of the technology. The specialized equipment and expertise needed to apply DLC coatings can be expensive, and this may make the technology less accessible to smaller medical device manufacturers or those with limited bu
46、dgets.However, it is important to consider the potential cost savings associated with DLC-coated devices in the long term. Increased wear resistance and reduced friction can extend the lifespan of medical devices and reduce the need for replacements, which can be costly for both patients and healthc
47、are providers.In addition, the potential benefits of DLC coatings for patient outcomes cannot be overlooked. Improved biocompatibility can reduce the risk of adverse reactions in patients, and the enhanced performance of DLC-coated devices can improve the accuracy and precision of medical procedures
48、.To overcome the challenges associated with DLC coatings in medical devices, collaborations between industry experts, researchers, and medical device manufacturers are crucial. By pooling resources and expertise, these groups can work together to develop and implement cost-effective DLC coating tech
49、nologies that optimize device performance while ensuring patient safety and efficacy.Overall, the potential benefits of DLC coatings for medical devices are numerous and significant. With careful consideration of the challenges and risks associated with their use, continued research and collaboration can help to expand the use of DLC coatings in the medical industry and improve patient outcomes.Another challenge that hinders the widespread adoption of DLC
