From legal update 130:
Officers are reminded that unless exempt under MCL
750.231, a person with a “mechanical knife” may still be
arrested for carrying a concealed weapon pursuant to
MCL 750.227 if that knife could be classified as a
“dagger, dirk, stiletto, or double edged non-folding
stabbing instrument of any length.” However, the fact
that the knife is “mechanical” is irrelevant to that offense.
This seems to suggest a double edged OTF knife for example is legal since it is "mechanical?"