One of the topics of implantology is biocompatibility, i.e. the limitation of unwanted interaction of the implant with the tissue. This includes, for example, reducing friction, wear, corrosion and ion release. Both joint implants and implants that are in contact with blood (stent, artificial heart valve) are affected. The issue of the implant-bone interaction is dealt with in bigger detail in: "Piezoelectric materials for bone implants". It can be solved by means of coatings based on diamond-like carbon (DLC). DLC coatings are an amorphous form of carbon that has some diamond-like properties. They have high hardness and corrosion resistance, a very low coefficient of abrasion, and are optically transparent, non-toxic and biocompatible, making them an ideal material for coating implants to improve their properties for medical applications. DLC layers could be used in orthopedics, cardiovascular surgery, ophthalmology and other areas of medicine.
This potential use is, however, limited by the existence of high levels of internal stress in the DLC structure. In our laboratory, we are investigating solutions using doping (homogeneous or gradient, in which the surface doping concentration is lower than the bulk concentration). We use chromium, titanium, nitrogen or silver. Each dopant provides slightly different properties, for example silver provides additional antibacterial activity. Dopants are prepared by combining the fluxes of two materials, i.e. carbon and the dopant. We use pulsed laser deposition (PLD) methods for both materials or a combination of PLD for carbon and magnetron sputtering techniques for dopant. These technologies allow a wide choice of dopant with arbitrary concentrations.
Dual pulsed laser deposition (carbon and silver)
Combination of pulsed laser deposition and magnetron sputtering methods