Miniature soft jumping robots made by additive manufacturing

Abstract

Abstract Fleets of insect-scale robots could navigate space-constrained environments for future applications in agriculture and maintenance. Long distance jumping expands the mobility of small robots. However, the performance of miniature jumpers is hindered by small-scale manufacturing processes and the limited library of design rules, materials, and actuators available at that scale. The intricate components in these robots are produced by manual assembly of miniature components, which imposes design constraints and causes mass inefficiency, reducing the overall system performance. Here, we combine bioinspired kinematic design, coiled artificial muscle actuators, and projection additive manufacturing (AM) to produce a monolithic elastomeric robot design. The fully elastomeric design, inspired by the kinematics of the locust jumping mechanism, can store elastic energy throughout the robot body before releasing it in the form of jumping kinetic energy, thus offering high energy storage density, miniaturization, and lightweight. Enabled by high-speed, production-grade AM, we designed and tested a fleet of 108 robot designs. The smallest tested robot has a length of 7.5 mm, a mass of 0.216 g, and jumps 60 times its body size in horizontal distance. A reduced-order model is developed to predict the compliant robot jumping distance, which agrees well with the experimental results. The jumping is driven by onboard coiled artificial muscles connected to a latch-triggering mechanism. Moreover, the robot can jump while carrying an integrated control system and power source to enable self-triggered jumping. A proof-of-concept motor-driven launch base is used to store large elastic energy in the robot. Overall, the combination of elastomeric AM, coiled artificial muscles, and an integrated triggering mechanism enables the production of fleets of high-performing miniature jumping robots.