University of California

Himont Incorporated

Stephen L Kaplan

Kyriakos Komvopoulos

Lisa A Pruitt

Catherine M Klapperich

Peter W Rose

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

The present invention includes a plasma reactor chamber, which is generally constructed such that a large opening exists in a wall of the chamber. The reactor chamber is deployed remotely from a control console, such as on a robotic arm. A plasma generating means, such as RF electrodes is disposed within the chamber and a flexible vacuum seal is engaged to the outer edge of the chamber wall, surrounding the opening. Operating components, such as a vacuum pump, plasma gas supply and RF generator are disposed within the control console, and various supply lines join the operating components to the reactor chamber. In operation, the reactor chambler is placed against a portion of a surface that is to be treated, and a low pressure plasma is created within the chamber to treat the zone of the surface enclosed within the seal of the chamber. Particularly shaped seals for irregularly shaped surfaces and a rolling seal for movement of the reactor chamber relative to a surface are within the contemplation of the invention.

Growing community of inventors

San Carlos, CA, United States of America

Stephen L Kaplan