They develop a “living ink” that is 3D printed and reproduced

3D printing has enormous potential for its ability to save time, facilitate prototyping, and use different materials to create products. One of the keys to the industry is research new materials to use as ink, beyond conventional polymers.

Now, a team from Northeastern University have created a “living ink”, developed from microbes, that is capable of reproducing itself, which would have numerous applications. According to Neel Joshi, lead developer, the idea is to mimic nature’s behavior using 3D printers.

“A tree – explains Joshi in an interview – has cells embedded in its interior and goes from being a seed to a tree by assimilating the resources of its environment to build a structure. What we want to do is something similar, but providing DNA in the ink.”

That DNA Joshi refers to is the ink itself, created from a genetic modification of the Escherichia coli bacteria. Thanks to this and as it happens in trees, the ink produces two different types of polymers, capable of crosslinking each other (that is, of forming a three-dimensional network) to create structures.

The interesting thing, as it happens in nature, is that this ink can increase in size (grow) and heal itself (to regenerate).

“You have to think of this ink as a platform to build many different things, not just bricks – adds Joshi -. Inspired by biology, it is possible to do wonderful things. Hair, for example, is made up of keratin, a protein that also forms the horns of a deer or rhinoceros. That is, they are made of similar materials, but they have very different functions. Yes, biology has discovered how to adjust mechanical properties using a limited set of building blocks.”

The researchers say that, with the right conditions, the cells of the microbial gel could reproduce. “Unlike concrete or plastic structures, for example, living systems would be autonomous – says Joshi -, they would adapt to the signals of the environment and they would be able to regenerate. This could lead to buildings that repair themselves.”

All this would serve, for example, to produce materials capable of release an anticancer drug every time it encounters a certain chemical stimulus and another thought to trap the toxic Bisphenol A (the famous BPA).

It could also be used for the space industry, especially in environments where the available materials do not give much space to create habitable structures.