The biological engine "muscle" is built from biomolecular motors called motor proteins.It is expected to be applied industrially because it performs mechanical work with high efficiency using the energy source of living organisms, but it has not been put into practical use due to the stability and preservation of muscle cells and technical problems.In addition, although the constituent molecules of muscle tissue have been mostly identified, the technique for reconstructing muscle from those molecules was unknown.

　This time, the research group has developed a molecular system that freely forms artificial muscles, inspired by the process of forming contractile fibers in the body.Kinesin, a type of motor protein, was modified into a filament and mixed with microtubules (a protein that acts as a rail for transportation) to form artificial muscles in a self-organized manner.Furthermore, the filamentization of the motor molecule was started by light irradiation, and artificial muscle could be formed only at the irradiated site.We succeeded in driving a micromachine by forming this artificial muscle in a mechanical structure with a size of several millimeters.

　In the research, we constructed motor protein molecules, which are the motor elements of living organisms, in tissues of several millimeters or more, and made it possible to produce artificial muscles with functions and properties similar to those of living organisms.In particular, since the formation of artificial muscles can be started by light irradiation, for example, if it is incorporated into a stereolithography type 3D printer, it will be possible to perform stereolithography of artificial muscles.In the future, it can become the basic technology of 3D printing technology for microrobots and soft robots driven by biomaterials, so it is said that it will overcome the challenges for mounting on robots.

Paper information:[Nature Materials] A printable active network actuator built from an engineered biomolecular motor