Using a 3D bioprinter, a group of engineers at Chalmers University of Technology have created objects made entirely by cellulose. The additive manufacturing process could be used to build patient-specific implants, new sensors, and wound dressings that communicate with healthcare workers.
Because cellulose does not melt when heated, the biodegradable material has not been used previously in additive manufacturing.
To address the challenges with cellulose, the Chalmers researchers mixed cellulose nanofibrils in a hydrogel consisting of 95-99 percent water. The gel could then be dispensed into the researchers’ 3D bioprinter, a technology which was earlier used to produce scaffolds for growing cells.
The Chalmers team next needed to dry the printed gel-like objects without having them lose their three-dimensional shape. The researchers froze the objects and removed the water.
Additionally, the cellulose gel was mixed with carbon nanotubes to create electrically conductive ink after drying. Using the two gels together, one conductive and one non-conductive, and controlling the drying process, the researchers produced three-dimensional circuits. The two gels together provide a basis for the possible development of a wide range of cellulose products with in-built electric currents.
