Periodic Reporting for period 1 - HePULSE (High-Performance Biocompatible Ag-DLC Coatings - Precise and Localized Silver Doping Through Novel Helium Pulse Injections)
Período documentado: 2021-02-15 hasta 2023-02-14
The problem is important to society in terms of individuals’ health, healthcare costs, and environmental concerns. The excess of Ag leached into the human body may increase cytotoxicity risks for an individual’s health. The compromised mechanical performance shortens the implant life. Revision surgery not only puts a financial burden on the medical system but also may not be suitable for every individual in the context of clinical conditions, especially focused groups like elderly people. The revision surgeries also increase environmental challenges as the cost and resources of medical waste management increase for safe handling and disposal of retired implants.
We have identified that Ag is essential for the early post-surgery phase, thus it would be highly beneficial to develop a coating where Ag is only doped ‘as required’, providing maximum biological performance without reducing DLC strength. Selective Ag doping in a DLC matrix is challenging through established physical vapour deposition techniques. Hence, the overall objective is to develop a novel DLC coating with precise and localized doping of Ag nanoparticles simultaneously doped in a one-step process using the sputtering method. The mechanical and biocompatibility performance of the new coating design is to be validated against typically made Ag/DLC coatings. Other objectives include the professional development of the individual fellow to transform him into an expert and future leader of high-performance surface coatings by receiving professional trainings and qualifications in the subject area.
The HePULSE project has successfully developed a new Ag/DLC as depicted in the image section, which is 63% harder, 21% more biocompatible, and uses a small amount of silver as low as 2 at.% when compared to typically deposited 17 at.% Ag/DLC coatings. The individual fellow received professional trainings, particularly from Advanced HE, UK and FOSTER, EU, attended the academic events and exhibitions on a subject area and achieved the teaching qualification as Fellow of Higher Education Academy, UK before securing a permanent role as a faculty member of a prestigious university in UK.
The new Ag/DLC coatings were made with sputtering and precise shutter control to embed Ag particles and correspondingly tested with TEM, FESEM, EDX, XRD, nanoindentation, absorbance, cell viability, and counting bacterial colonies. A series of typical Ag/DLC was made with doping of 17, 40 and 65 at.% Ag in DLC matrix for comparative study. The new Ag/DLC design made in this project suggests that a small amount of Ag i.e. ~ 2 at.% releases a similar amount of Ag ions as released by typically made Ag/DLC design with 17 at.% Ag concentration. Further, the new Ag/DLC coating using 2at.% Ag is 63% harder, 21% more biocompatible, and shows adequate antimicrobial features when compared to typically deposited 17 at.% Ag/DLC coatings. The project outcomes are disseminated through journal articles (1) Soft diamond-like carbon coatings with superior biocompatibility for medical applications, Ceramics International – published (2) Biomechanical Characteristics of Silver Enriched Diamond-like Carbon Coatings for Medical Applications, Journal of Alloys and Compounds – Revision submitted JALCOM-D-22-17359R1 (3) A New Design of Precision Silver Doped Diamond-Like Carbon Coating with Superior Bio-Mechanical Performance – submitted CARBON-S-23-01114, and (4) Multi-functional bioactive diamond-like carbon coatings for medical implants, Biomaterials – submitted jbmt63755. The project work is also disseminated through presentations at Northumbria University and international conferences (1) The Korean Society of Mechanical Engineers Annual Meeting 2022 - ICC JEJU, Jeju, Republic of Korea and (2) International Conference on Advances in Design, Materials and Manufacturing Technologies 2022, Hong Kong. The project data is available with Open Access and DOI identifiers at Northumbria University institutional repository powered by Figshare.
The fellow has received FOSTER EU Open Science, Advance HE Gender and Research Design trainings, attended CPD events by IET, IMechE, Surface Venture, and European Researchers Night, wrote outline proposals, mentored PhD students, performed teaching and learning activities, learned TEM and FIB experimentation during secondments at Durham University, networked with industrial partners such as IHI IONBOND AG, Switzerland, Teer Coating UK, Moorfiled Nanotechnology, UK and achieved FHEA teaching recognition.