Scientists working at the Massachusetts Institute of Technology (MIT) have managed to combine advances in 3D printing technology with breakthroughs in genetic engineering, to produce bacteria which function in a similar manner to switches in a CPU.
The bacteria have been engineered to adapt to a number of different stimuli and can take a myriad of different forms, thanks to 3D printing. These advances were made possible by the advent of two different technologies. The first of these was a gel, made up of water and various nutrients, in which the bacteria could survive for long periods. Once this gel had become available, the scientists began developing a 3D printer which would be able to use the gel as an ink for printing 3D onto the surfaces of various materials.
Testing the engineered bacteria involved altering a number of them so that they would change between different colors upon contact with three specific chemicals. Once this had been done, the three groups were printed in a branching shape. Meanwhile, the three chemicals were spread onto a human hand so as to cover its skin surface. Once that was done, the bacterial branching shape was pressed onto the human skin.
Results were not instantaneous, but after a few hours had passed, the bacterial structure’s branches began to light up in the color corresponding to the chemical they had made contact with.
Although this is not the first time scientists and engineers have been able to print 3D objects using living cells, it is certainly one of the more successful ones. The success of this research indicates a probable higher success rate of 3D printing using bacterial cells as opposed to those of mammals, which are considered to rupture easily due to their general weakness. Such cells face a
high risk of dying during the printing procedure, whereas the bacteria used at MIT were able to live for a whole day after the experiment had been conducted. It is in fact possible that they may live even longer – results are currently limited as MIT stopped testing the cells one day after printing.
While practical applications of the technology may be limited at this early stage, the potential is there to make a wide impact. With further work and development, scientists at MIT hope to put the bacteria to use in the same way as switches in a computer, allowing for them to be used in the encoding of logic. One example of this could be a simple logic gate. When triggered, a first bacterial cell would secrete a chemical which, in turn, would stimulate a second cell. In this case, the logical representation of the chemical detection would be a 1. Should the second cell fail to detect the target chemical, this would represent a logical output of 0.
Simple logic gates such as these are the building blocks of most of the world’s computational power, although they are primarily built using materials such as silicon, and function electronically. The future development of biological alternatives opens the door to ingestible ‘computers’ or ‘robots’ for public health benefits.