Well, the work was created by Karel Capek.

In Czech language `robota` means forced labor for your lord. Robotnik is just guy performing it, it is not used in other way in Czech language.

The word came from Czech, first use being from Karel Capek (checked some more sources, including the work from Sevan Nişanyan[1], an Armenian-Turkish language researcher, who would probably be unbiased in this matter).

Another language with the same word used with a closer meaning does not always mean there is a connection. Etymology usually discovers connections which aren't intuitive at all.

[1]: (Turkish) http://www.nisanyansozluk.com/?k=robot&x=0&y=0

Yeah, actually this is how I remembered it from Webster's Third International many years ago, which I don't have anymore. Since then, I've become reliant on etymonline, which is handy, but somebody's hobby project[0]. A good reminder to trust the memory over the internet once in a while.

[0] http://etymonline.com/bio.php

Fun fact, words 'slave' and 'Slav' comes from same word.

It's "rabotnik" in Russian, and remarkably, "rab" does mean "slave". Czech is too distant however so any verbatim parallels are useless here.