Well, I figured I'd Google it to see if anyone was working on it, and yes, someone has done it. it's not small enough to fit the reactor on your DeLorean just yet, but wait a few years... Anyhow, here's the article on the real thing:
http://www.cinemablend.com/technology/Purdue-Scientists-Give-The-World-Mr-Fusion-2671.html
http://www.cinemablend.com/technology/Purdue-Scientists-Give-The-World-Mr-Fusion-2671.html