To add some sense of time and scale here, an article on the same project from 2010:

http://www.sfgate.com/health/article/UCSF-team-working-on-ar...

Bioartifical kidneys are nowadays competing with the organoid approach. For chemical factory and filter organs, the artifical organ doesn't have to look anything like the real thing in order to perform at least some of its functions.

So for example, now that researchers can forge tiny functional kidney organoids ( http://dx.doi.org/10.1038/protex.2015.087 ) they can chain these things together into useful structures for implant or use inside biomaterial enclosures.

There is definitely a spectrum between materials science and biology, with hypothetically practical devices possible at all points and the line between device and organ very blurry. The biology end is putting more competitive pressure on the materials science end these days.