Fig. 1: Muscle-inspired elasto-electromagnetic (EEM) mechanism for insect-scale soft robots.

a The maximum output force and contraction ratio of animals and autonomous actuators at insect-scale. The contraction ratio of animal muscles is between 10% and 30%. b Inspired by the contraction and relaxation of muscles, the EEM mechanism mimics these dynamics by balancing the magnetic attractive force, \({F}_{{{{\rm{e}}}}{{{\rm{m}}}}}\), and the elastic response of the soft structure, \({F}_{{{{\rm{e}}}}}\). c Inspired by the structure and locomotive gaits of small animals, autonomous soft robots are designed as an inchworm crawler, legged crawler, and swimmer, each showcasing high force output, large contraction ratios, and enhanced energy efficiency. These autonomous small robots with sensors integrated show great potential in applications like search-and-rescue, cave discovery, and environmental detection. Source data for (a) is provided as a Source Data file.