The printer uses fiber soaked with UV curable resin and then extruded trough toolhead with UV lights.
"Think of this machine as a very friendly sculpting spider."
Here is the extrusion head solidifying the UV resin:
Prints are still a very rough but the concept works and is under development.
Here is Instructables page with much more details on The Bug:
Also check out Sebastians homepage with many other cool projects : http://www.adorevolution.com/