Engineers use DNA to create "realistic" machines

As genetic material, DNA is responsible for all known lives. But DNA is also a polymer. By exploiting the unique nature of the molecule, Cornell engineers have created simple machines built from biomaterials and possessing the properties of living things.

Using what they call DASH materials (DNA-based assembly and hierarchical synthesis), Cornell engineers built a DNA material with metabolism capabilities, as well as self -assembling and organizing – three essential traits of life.

"We are introducing a whole new concept of realistic material, fueled by its own artificial metabolism – we are not creating something alive, we are creating much more realistic materials than ever before," said Dan Luo, professor of engineering. Biological and Environmental College College of Agriculture and Life Sciences.

The document, "Dynamic DNA Material with Emerging Locomotion Behavior Powered by an Artificial Metabolism", published April 10 in Robotic science.

For any living organism to survive, there must be a change management system. New cells must be generated. old cells and waste must be swept away. Biosynthesis and biodegradation are key elements of self-sufficiency and require a metabolism to maintain its shape and functions.

Thanks to this system, the DNA molecules are synthesized and assembled in patterns in a hierarchical way, which allows to perpetuate a dynamic and autonomous process of growth and degradation.

Using DASH, Cornell engineers created a biomaterial that can emerge autonomously from its nanoscale building blocks and organize itself – first in polymers, then in medium-scale shapes. Starting from a basic nucleotide sequence of 55 nucleotides, the DNA molecules were multiplied hundreds of thousands of times, creating repeated DNA strings of a few millimeters. The reaction solution was then injected into a microfluidic device providing a flow of liquid energy and the elements necessary for the biosynthesis.

As the flux covered the material, the DNA synthesized its own strands, its increasing growing end and its degrading end in an optimized equilibrium. In this way, he has made his own locomotion, crawling forward, countercurrently, in the same way that slimy molds are moving.

Locomotive capability has allowed researchers to pit sets of materials against each other during competitive races. Due to the randomness of the environment, one body would gain an advantage over the other, allowing it to cross the finish line first.

"The designs are still primitive, but they have shown a new way to create dynamic machines from biomolecules, and we are at the first stage of building realistic robots by artificial metabolism," said Shogo Hamada, speaker and associate. research at Luo's laboratory. and corresponding co-author of the article. "Even from a simple design, we have been able to create sophisticated behaviors like racing.The artificial metabolism could open a new frontier in robotics."

Engineers are currently studying ways to have the material recognized by the equipment and to search for it autonomously in the case of light or food, or to avoid it if it is harmful.

The programmed metabolism embedded in the DNA materials is the key innovation. The DNA contains the set of instructions for metabolism and autonomic regeneration. After that, it's all alone.

"Everything, since his ability to move and be competitive, all these processes are autonomous.There is no outside interference," said Luo. "Life began billions of years from maybe a few types of molecules, it could be the same thing."

The material created by the team can last two cycles of synthesis and degradation before its expiration. According to the researchers, longevity could probably be extended, thus opening up the possibility to more "generations" of material as it recurs. "In the end, the system could give rise to reproducible and realistic machines," Hamada said.

"In a more exciting way, the use of DNA gives the whole system a possibility of self-evolution," Luo said. "It's huge."

Theoretically, it could be designed so that subsequent generations appear in seconds. Reproduction at this accelerated rate would take advantage of the natural mutation properties of DNA and accelerate the evolutionary process, according to Luo.

In the future, the system could be used as a biosensor to detect the presence of any DNA or RNA. The concept could also be used to create a dynamic model for making proteins without living cells.

A patent is pending with the Center for Technology Licensing.