Scientists at the University of the West of England are working on the design of a biological robot based on slime molds.
Previous research on slime molds has already shown their capability to solve complex computational tasks such as shortest path and maze problems and even been used to control a robot. Slime molds have also been shown to be able to transport objects using oscillating tubes.
The new robot, affectionately named PlasmoBot, will be able to "pick up" objects by engulfing them with the final goal to achieve micro-assembly. While still far off, fully biological amorphous robots would be massively parallel and would come with many built-in advantages over their silicon counterparts, including cheap replication, self-healing, and - naturally - bio-degradability.
Slime molds UWE: http://info.uwe.ac.uk/news/UWENews/arti ... &year=2009
Also check some older stuff on slime mold controlling a hexapod: http://eprints.ecs.soton.ac.uk/11749/1/ ... ToCell.pdf