University of California

International Business Machines Corporation

Kyriakos Komvopoulos

Ian G Brown

Bo Wei

Andre Anders

Simone Anders

Satomi Tajima

Stephen L Kaplan

Lisa A Pruitt

Catherine M Klapperich

C Singh Bhatia

Marilee Brewer

Zhu Feng

Singh C Bhatia

Methods for treating surfaces of polymeric substrates (as used in medical implants) with inert plasmas to promote the growth of bioentities (such as cells) on these surfaces is disclosed. The treated surfaces are subsequently exposed to an environment to form functionalities associated with enhanced growth of the bioentity on the surface. For example, the substrate may be exposed to the ambient environment. The bioentity may then be deposited on the modified surface. This inert plasma treatment and exposure to a suitable environment does not degrade the implants, and thus improved implants are created. Also, due to the specific functional groups at the modified surface, high cell densities are achieved.

Method to control cell adhesion and growth on biopolymer surfaces

Methods and systems for modifying a surface of a polymer with a shielded plasma are provided. The surface may be modified to create a surface with increased crosslinking and/or a particular mechanical property, such as a coefficient of friction. A shielding arrangement is used to modify the plasma to which the polymer surface is exposed, thereby providing a surface with the desired mechanical properties. In one aspect, a single source that provides multiple species of plasma particles is advantageously used instead of having to switch or move in multiple sources. The extent of crosslinking is evaluated using a surface force microscope to determine a frictional property that is correlated to the crosslinking, e.g., via calibrated values determined from reference surfaces.

Modification of polymer surface with shielded plasma

A method for forming a carbon-containing layer on a polymeric substrate is disclosed. The polymeric substrate is modified physically and chemically using an inductively coupled plasma process. The carbon-containing layer can be fluorocarbon film with different physicochemical properties and structure.

Method for depositing fluorocarbon films on polymer surfaces

The surface of a high molecular weight polymer such as high molecular weight polyethylene is modified in a localized manner by treatment with a plasma gas. The treatment produces a variety of useful results, depending on the gas used and the treatment conditions. One such result is crosslinking of the polymer in a localized manner at the surface to improve the durability of the surface against detrimental processes such as reorientation and alignment of the crystalline lamellae parallel to the contact surface which renders the surface susceptible to disintegration into particles. Another result is the chemical transformation of the surface for purposes such as increasing the hydrophilic or hydrophobic nature of the surface or coupling functional groups to the surface.

Plasma-assisted surface modification of polymers for medical device applications

A process for producing an article with improved ceramic surface properties including providing an article having a ceramic surface, and placing the article onto a conductive substrate holder in a hermetic enclosure. Thereafter a low pressure ambient is provided in the hermetic enclosure. A plasma including ions of solid materials is produced the ceramic surface of the article being at least partially immersed in a macroparticle free region of the plasma. While the article is immersed in the macroparticle free region, a bias of the substrate holder is biased between a low voltage at which material from the plasma condenses on the surface of the article and a high negative voltage at which ions from the plasma are implanted into the article.

Surface treatment of ceramic articles

Surface modification of magnetic recording heads using plasma immersion ion implantation and deposition is disclosed. This method may be carried out using a vacuum arc deposition system with a metallic or carbon cathode. By operating a plasma gun in a long-pulse mode and biasing the substrate holder with short pulses of a high negative voltage, direct ion implantation, recoil implantation, and surface deposition are combined to modify the near-surface regions of the head or substrate in processing times which may be less than 5 min. The modified regions are atomically mixed into the substrate. This surface modification improves the surface smoothness and hardness and enhances the tribological characteristics under conditions of contact-start-stop and continuous sliding. These results are obtained while maintaining original tolerances.

Surface treatment of magnetic recording heads

A process is disclosed for the pretreatment of a carbon-coated substrate to provide a uniform high density of nucleation sites thereon for the subsequent deposition of a continuous diamond film without the application of a bias voltage to the substrate. The process comprises exposing the carbon-coated substrate, in a microwave plasma enhanced chemical vapor deposition system, to a mixture of hydrogen-methane gases, having a methane gas concentration of at least about 4% (as measured by partial pressure), while maintaining the substrate at a pressure of about 10 to about 30 Torr during the pretreatment.

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Orinda, CA, United States of America

Kyriakos Komvopoulos