biotechnology is the exploitation of biological processes for industrial and other purposes, especially the genetic manipulation of microorganisms for the production of antibiotics, hormones, etc.
it has nothing to do with mechanical and metal alloy robotics. what you are thinking about is bio-synethic cybernetics in other words cybernetic enhancements made not from metal and other such materials but nano cellular machinary made from carbon laticuse and what not essentially a cyborg made out of nothing but living tissues and organic material kind of like the cellular chips the clones have implanted in them in the star wars the clone wars.