3D printing with bacteria creates bone-like composite

Researchers at the Technical University of Lausanne (EPFL) have developed a method for 3D printing with an ink made from calcium carbonate-producing bacteria. The resulting printed bio-composite is strong, lightweight and environmentally friendly. EPFL reports this in a press release.

Strong bio-composite materials found in nature are light, strong, porous and rigid. Examples include shells or bones. Producing such materials in a laboratory environment has proven very difficult. Therefore, EPFL researchers opted for a solution from nature: using the sporosarcina pasteurii.

BactoInk

The “BactoInk” works by exposing these bacteria to a solution containing urea, which triggers a mineralization process. This process produces calcium carbonate (CaCO3). With this, almost any imaginable shape can be printed, after which curing through the mineralization process takes several more days.

Esther Amstad, head of the soft materials laboratory at EPFL, explains that by no means every material is suitable for 3D printing. This is because the ink must be liquid. “3D printing is only possible if a material is liquid enough to press through the 3D printing head, but then hardens without changes.”

Previously, many structures were often too soft, or shrank. This shrinking causes cracks and loss of shape and is therefore undesirable. Because these bacteria start a mineralization process that cures slowly over a period of several days, these problems are not present. To ensure that the final product contains no bacteria, the product is given an ethanol bath at the end of the process.

Using 3D-printed microalgae to make artificial leaves

An international research team led by the Delft University of Technology (the Netherlands) has used 3D printers to turn algae into living leaves.

Art restoration and artifical coral

One application lies in art restoration. Because it is possible to inject this material into a mold, you can seal cracks in vases, for example. It could also be made into artificial coral, which could help restore coral reefs. Furthermore, this the composite material resembles bone, making biomedical applications also possible.

Amstad thinks this versatility in particular, combined with its low environmental impact, is going to ensure that this material will be widely used. “There are so many possibilities because of its light weight, strength and similarities to natural materials,” Amstad said.

© Image Eva Baur