Surface treated shape memory materials and methods for making same
AssigneesVersitech Limited, City University of Hong Kong
InventorsKelvin W. K. Yeung, Ray W. Y. Poon, Paul Kim-Ho Chu, Kenneth M. C. Cheung, William W. Lu
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Abstract
The invention provides a method for making surface treated shape memory materials such as from NiTi alloy using plasma immersion ion implantation and deposition and related ion-beam and plasma-based techniques to alter the surface properties of those materials primarily for biomedical applications. The surfaces are treated with nitrogen, oxygen, and carbon, but become bio-inactive after implanted with other elements such as silicon.
Claims25
A method for altering the surface composition of a nickel titanium alloy part to increase biocompatibility, comprising exposing the surface of the nickel titanium alloy part to nitrogen, oxygen, or carbon by plasma immersion ion implantation, plasma immersion ion implantation and deposition, or ion beam immersion or implantation;
- whereby nitrogen, oxygen, or carbon ions bombard and penetrate the surface at a depth of at least about 50 nm, being implanted into the subsurface by acceleration under the influence of an electric field, and whereby the altered surface composition exhibits increased cell adhesion as compared to the unaltered surface composition.
A method for altering the surface composition of a nickel titanium alloy part to increase biocompatibility, comprising exposing the surface of the nickel titanium alloy part to nitrogen, oxygen, or carbon by plasma immersion ion implantation, plasma immersion ion implantation and deposition, or ion beam immersion or implantation;
- whereby nitrogen, oxygen, or carbon ions bombard and penetrate the surface at a depth of at least about 50 nm, being implanted into the subsurface by acceleration under the influence of an electric field, and whereby the altered surface composition exhibits decreased cell apoptosis as compared to the unaltered surface composition.
A method for altering the surface composition of a nickel titanium alloy part to yield the improved surface mechanical properties of increased hardness and improved corrosion resistance comprising exposing the surface of the nickel titanium alloy part to nitrogen, oxygen, or carbon by plasma immersion ion implantation, plasma immersion ion implantation and deposition, or ion beam immersion or implantation;
- whereby nitrogen, oxygen, or carbon ions bombard and penetrate the surface at a depth of at least about 50 nm, being implanted into the subsurface by acceleration under the influence of an electric field, and whereby the altered surface composition exhibits increased hardness and improved corrosion resistance as compared to the unaltered surface composition.
Dependencies are inferred from the claim text.