I've been watching a few different Star Trek series lately, and have noticed a similar plot device throughout each series. Many episodes within the various series have the crew try to find someone, and discover that they have removed their combadge. This seems like a very unreliable method of locating people.

With the way they portray the Federation in all its scientific glory, you'd think they would have made a better method of locating someone aboard a ship/space station. Why not integrate that same technology within the very uniform someone wears, or better yet locate them by their bio-signature?

Why didn't the producers of the show eventually catch on and just use another method of locating people?