I’m wondering if using peltier modules is legal I can’t seem to find anything saying its not so I believe it is.
Why are you using it? That might help you determine legality. Also, does it fit the cost rules?
Is your robot serving cold beverages? 
Do you have an overheating issue with motors, Jaguars or Victors?
Maybe a shape memory alloy mechanism?
I guess it’s technically a custom circuit. If you put a 20A breaker and it costs less than $400, it’s probably OK.
Follow the flow chart at the end of Section 8 of the Game Manual and see where you end up…
Make sure you are using a copy of the latest flowchart btw!
There was an update early on to that.
I’m not sure whether this made it to FIRST Q&A last year (as Al Skierkiewicz suggested). However, the GDC has often stated that prior year’s rules may not apply this year.
My comments from previous years apply…http://www.chiefdelphi.com/forums/showpost.php?p=692207&postcount=7
Of special note is the "why do you need it?