Opensource would mean to relinquish all intellectual rights plus it could be seen as prior art in a patent later, so the fight to keep the patent would be weaker.
Thanks for the reply. I really believe in this technology that I've created and I want it to exist. I would like to be the person to make that happen, but if my universities gets all the IP, I just don't see it going anywhere. I'd rather give it all away for free to everyone then let the university control it.
If your university were particularly malicious, they could sue you for giving away their intellectual property - after all, they have legal rights to it. It's also potentially career suicide if you ever wanted to pursue a career in academia.