Through the long process of evolution, animals have acquired flexible movements that adapt to complex physical environments.On the other hand, the movement characteristics of these animals are not well understood due to the lack of progress in the development of experimental systems that can reproduce their ingenious mechanisms.

　In particular, this research focused on peristalsis, which is one of the typical movements exhibited by animals.Until now, soft robots that mimic larvae have been developed using silicone resin, but they have not been able to move by peristalsis.In this study, we developed a soft robot with two improvements based on the Drosophila larva as a model.

　The first point of improvement is the use of a vacuum pump to contract individual somites in the same way as actual larvae (*conventionally, somites were expanded).The second point is that the abdomen of the larva has a spike-like structure, and it is thought that the friction of this structure is involved in the forward motion. is to incorporate

　As a result, we were able to reproduce the peristaltic movements of the Drosophila larvae by controlling the pressure in the somites of the developed soft robot with appropriate intensity and timing.In addition, larvae are known to move backwards more slowly than forwards, and this feature was also observed in the developed soft robot.

　Furthermore, by using this robot, we succeeded in showing that the contractile force of larvae is related to their locomotion speed.Conventionally, it was difficult to analyze the effect of the strength of the contractile force on motion. It was found that the stronger the force, the faster the movement speed.

　In this way, the use of soft robots is expected to contribute to the understanding of the physical mechanisms by which soft animals move skillfully.

Paper information:[PLOS ONE] A vacuum-actuated soft robot inspired by Drosophila larvae to study kinetics of crawling behavior