Researchers at Washington University in St. Louis have developed a new type of artificial muscle fiber. The fibers are made using synthetic biology, where proteins are fused into engineered microbes.

Artificial muscle fibers have long been a topic of interest as researchers try to design materials with muscle-like properties to suit a variety of application scenarios. Previously, MIT researchers used common polyamide fibers to create artificial muscle fibers that mimic the bending and movement properties of natural muscle tissue. The artificial muscle fibers produced by the team using microbes are stronger than cotton, silk, najlon, or even Kevlar.

Currently, engineered microorganisms can be used to produce small molecules, and direct use in the synthesis of high-performance polymer materials remains a challenge. The high-performance fiber designed by the researchers not only has the high damping properties of natural muscle protein, but also has high strength and toughness. It is understood that the key to building the material is to produce the protein.

Muscle group protein

To avoid some of the problems that normally prevent bacteria from producing large proteins, the team designed bacteria to splice together small pieces of the protein and then use a wet spinning process to turn the protein into fibers about 10 microns in diameter, or one-tenth the thickness of a human hair.

Multiscale structure of muscle and silicon-based polymerization of myoglobin in EScherichia coli

The article links: https://www.nature.com/articles/s41467-021-25360-6