Article used in contact with living body or biological sample, medical instrument, and artificial joint

A medical instrument comprising:

• an article used for a living body or a biological sample,
• wherein the article having:
• a first film;
• and
• a second film,
• wherein the first film includes an amorphous carbon film in which a proportion of the number of carbon atoms having an sp2-hybrid orbital to a total number of carbon atoms having an sp2-hybrid orbital and carbon atoms having an sp3-hybrid orbital is in a range of 23 to 43 atom % or a titanium-doped amorphous carbon film in which a proportion of the number of titanium atoms to the number of carbon atoms is in a range of 3 to 12 atom %, and
• the second film includes any one film selected from an amorphous carbon film in which a static contact angle with pure water is 10° or less, a titanium-doped amorphous carbon film in which a proportion of the number of titanium atoms to the number of carbon atoms is less than 3 atom % or greater than 12 atom %, or a titanium-doped amorphous carbon film in which a static contact angle with pure water is 10° or less.

An artificial joint comprising:

• an article used for a living body or a biological sample,
• wherein the article having:
• a first film;
• and
• a second film,
• wherein the first film includes an amorphous carbon film in which a proportion of the number of carbon atoms having an sp2-hybrid orbital to a total number of carbon atoms having an sp2-hybrid orbital and carbon atoms having an sp3-hybrid orbital is in a range of 23 to 43 atom % or a titanium-doped amorphous carbon film in which a proportion of the number of titanium atoms to the number of carbon atoms is in a range of 3 to 12 atom %, and
• the second film includes any one film selected from an amorphous carbon film in which a static contact angle with pure water is 10° or less, a titanium-doped amorphous carbon film in which a proportion of the number of titanium atoms to the number of carbon atoms is less than 3 atom % or greater than 12 atom %, or a titanium-doped amorphous carbon film in which a static contact angle with pure water is 10° or less.