December 4, 2017
Flink: The Latest 3D Printing Ink Powered With Bacteria [Video]

Researchers at the ETH Zurich laboratory developed a bacteria-infused ink and used it to 3D print various objects.

Led by Professor Andre Studart, ETH researchers presented a new 3D printing medium that uses live bacteria. They developed 3D printing ink that contains bacteria and made it possible to print objects without killing the bacteria in the process. These mini biochemical factories can be modified to possess certain properties, depending on which type of bacteria scientists put in the ink.

The scientists named this bacteria-powered ink medium "Flink."

Cleaning up environmental pollution, harvesting photosynthetic energy, and making medical supplies are some of the potential uses for "Flink" according to its creators as ScienceAdvances states.

The new ink is made up of a hydrogel that simulates the environment, as well as contains the essential nutrients, to keep the bacteria alive. The hydrogel allows the bacteria to grow and breed. Manuel Schaffner, one of the scientists at ETH Zurich, says that once the nourishment is all used up by the bacteria, the object can simply be dipped in the hydrogel to replenish the nutrients.

According to ETH Zurich, creating the perfect consistency was a challenge for the team of scientists. The stiffness of the ink will affect the bacteria's ability to move. They needed to create the ink that is fluid enough to pass through a pressure nozzle and allow bacteria to move. The object also needed to be strong enough support the weight of the layers on top of it. The printed object might collapse if the printed object is too fluid. In the end, the substance needed to be as sticky as toothpaste and as consistent as a popular hand cream.

Phenol is a toxic chemical that may cause conditions ranging from dermatitis to second and third-degree burns upon contact with skin. It is also harmful to the central nervous system, liver, and kidneys. One gram of this substance can be fatal to humans. The researchers 3D printed a grid infused with a breed of bacteria called Pseudomonas putida. When they placed this object in water contaminated with Phenol, the bacteria purified the water completely in a few days.

Another breed of bacteria called Acetobacter xylinum produces a gelatinous substance called bacterial cellulose. Medical practitioners use this substance for dressing wounds. The scientists 3D-printed a patch in a doll's face and then left the material in a sealed container for a few days. ETH Zurich food scientist Patrick Rühs observed that the object's surface produced a cellulose film. 3D-printing a cellulose patch to match the contours of body parts could prevent a wound dressing material from peeling off. Apart from that, there is also a lower possibility of wound infection due to the sealing property of the film.

Because of this, it is possible to create a breed of bacteria that produce substances according to human needs.