I hadn't read about that artificial heart design before. I'm guessing it's going to turn out badly though. There's probably some unrecognized dependency on the pumping behavior in some part of the circulatory system. Like, maybe arteries will harden much more quickly if they aren't regularly stretched, or cells won't dump their waste as efficiently without the changes in pressure in the capillaries around them.
Aside from the fact that the solar tree was debunked (as someone else pointed out), Stanford students doing something with a high speed camera is somehow less heartwarming than a 13 y.o. kid doing it for a science project.
We also rarely never see 360 degree rotating objects in animals, which is why hearts pump instead of containing rotating impellers, like newer artificial heart designs: http://news.yahoo.com/blogs/technology-blog/artificial-heart...