I would also recommend FDM/FFF for the creation of bio-composites.
You need to buy a filament extruder first:
I our lab we use the filastruder, which is low budget but works quite ok:
https://www.filastruder.com
You can also take a look a the extruder from 3DEvo.
After choosing one system I would recommend taking some time to find out the optimal extrusion parameters, since extrusion can be inconsistent at times which prohibits good printing quality later on.