Researchers at the Italian Institute of Technology (Instituto Italiano di Technologia or IIT) are developing a revolutionary new robotic prototype based not on specific human characteristics or capabilities but on those of plants. The “plantoid” simulates certain behaviors of plants linked to survival and growth using root- and leaf-like sensors that project from a 3D printed tree trunk embedded with a microcomputer.
More details on the Plantoid robot can be found here:

Check out a picture of the 3D printed trunk of the 'Plantoid' robot.