INK BUILDING INN : ADVANCE RESEARCH

 

Ink that goes beyond blueprints : It's the building. Made entirely of microbes it could eventually produce homes that heal themselves.

The combination of a printer [ the bane of office workers ] with bacterium E. coli [the scourge of romaine lettuce] may seem an odd, if not unpleasant, collaboration.

BUT scientists have recently melded the virtues of the infuriating tool and those of the toxic microbe to produce an ink that is alive, made entirely from microbes. The microbial ink flows like toothpaste under pressure and can be 3-D printed into various tiny shapes. - a circle, a square and a cone. - all of which hold their form and glisten like Jell-O.

The researchers describe their recipe for their programmable, microbial ink in a study recently published in the journal Nature Communications.The material is still being developed, but the authors suggest that the ink could be a crucial renewable building material, able to grow and heal itself and ideal for constructing sustainable homes on Earth and in space.

The new substance is not the first ever living ink. Scientists have previously created printable gels that were cocktails of bacteria and polymers that helped provide structure when printed.

One such ink contained hyaluronic acid, a seaweed extract and fumed silica - all agents that made the material thicker and more viscous.

But the new substance contains no additional polymers; it is produced entirely from genetically engineered E. coli bacteria. The researchers induce bacterial cultures to grow the ink, which is also made of living bacteria cells.

When the ink is harvested from the liquid culture, it becomes firm like gelatin and can be plugged into 3D-printers and printed into living structures, which do not grow further and remain in their printed forms.

''They developed this really nice engineered platform where the microbes secrete their own ink,'' said Sujit Datta, a chemical and biological engineer at Princeton University who was not involved with the research. ''The microbes are creating the material themselves - you just have to feed them and keep them happy.''

Bacteria may seem an unconventional building block. But microbes are a crucial component of products such as perfumes and vitamins, and scientists have already engineered microbes to produce biodegradable plastics.

A material like microbial ink has more grandiose ambitions, according to Neel Joshi, a synthetic biologist at Northeastern University in Boston and an author on the new paper.

Such inks are an expanding focus of the field of engineered living materials. Unlike structures cast from concrete or plastic, living systems would be autonomous, adaptive to environmental cues and able to regenerate - at least, that is the aspirational goal, Dr. Joshi said.

The Publishing continues. The World Students Society thanks author Sabrina Imbler.