From insect locomotion to precision actuation: A grasshopper midfoot-inspired design for enhanced step efficiency in piezoelectric stick-slip systems

A novel piezoelectric stick-slip actuator is designed, which incorporates the strong power output of the mid-foot of a grasshopper with excellent stride characteristics. The actuator utilizes a flexible hinge structure inspired by the mid-foot of a bionic grasshopper, which can achieve large load capacity and high stepping efficiency. Finite element analysis (FEA) is employed to complete the parametric design of the structure, and the rationality of the structure is verified by theoretical analysis. Furthermore, dynamical model is established to clarify the working process. Then, static and fatigue analysis of flexible hinge is completed. Experimental findings reveal that the prototype achieves a peak output speed of 17.28 mm/s and can support a maximum load of 1700 g, which is equivalent to 208 times its own weight of 8.14 g, and the stepping efficiency of the actuator is 99.04%. The findings fully validate the scientific validity and application of the mid-foot design concept in bionic grasshopper.