3D PRINTED BACTERIA PURIFY WATER OF TOXINS

Scientists in Switzerland have developed a new printing material that includes living bacteria. The material can be used to print small, biochemical purification plants.

TECHNOLOGY 

Materials researchers from the ETH Zürich Institute of Technology have developed a living 3D-printing media known as Flink. The scientists mixed bacteria and nutrients with hydrogel – a type of jelly – which keeps everything together.

Using the material, they can print 3D structures of any shape and equip the structure with up to four different bacteria at a time and brand new characteristics.

In an experiment, the scientists demonstrated two different ways of using the material. They printed a small net with bacteria which can break down phenol, a toxin in pesticides, which threatens streams and lakes. It is already common to make bacteria break down phenol – and other chemical pollution – but weaknesses are involved: It is difficult to keep track of where the bacteria are in the water, and the bacteria need energy in the shape of nutrients which do not always exist where they are placed.

With the new printing material, a reusable net of bacteria can be placed in the water, and the bacteria even bring their own food.

The scientists also printed a customised patch using a bacterium, which produces wound-healing cellulose. Instead of flat patches, which are inconvenient on elbows and heads, the printer can use Flink to get the right fit.

HOW THE 3D PRINTER PRINTS BACTERIA

First, the scientists select the bacteria that they wish to use.

1. The bacteria are nourished and propagated in jars.
2. Hydrogel is added to the bacteria to produce ink.
3. The 3D printer prints the ink in the required shape.

Published in "Science Illustrated", Australia, issue 58, April, 5,2018, excerpt p.17. Digitized, adapted and illustrated to be posted by Leopoldo Costa.