Abstract

Several efforts have been made to develop walking smart soft robots through different strategies such as the use of complex aligned magneto-active materials. Here, we show a simple approach for the design of a smart soft robot using an elastomer film with randomly distributed ferrimagnetic nanoparticles able to be remotely controlled by a magnetic field. The magneto-active robot has a rotating-square kirigami geometry resulting in a flexible smart auxetic metamaterial (i.e., a negative Poisson-ratio structure). Alongside the standard translational locomotion on a smooth-surface under a steady magnetic force, the auxetic kirigami structure mimics the crawling-locomotion of worms over a high-roughness surface under an oscillatory horizontal field, even climbing vertical-obstacles. A theoretical understanding for this new locomotion mechanism stresses the relevance of the kirigami metamaterial design and the ferrimagnetic response of the particles. The soft robot can also transport a payload having weights higher than the weight of the smart elastomeric film. The smart auxetic structure further presents a rolling locomotion by properly orienting the magnetic field, meaning multiple remote locomotion mechanisms.