Insects maintain remarkable agility after incurring severe injuries or wounds. Although robots driven by rigid actuators have demonstrated agile locomotion and manipulation, most of them lack animal-like robustness against unexpected damage. Dielectric elastomer actuators (DEAs) are a class of muscle-like soft transducers that have enabled nimble aerial, terrestrial, and aquatic robotic locomotion comparable to that of rigid actuators. However, unlike muscles, DEAs suffer local dielectric breakdowns that often cause global device failure. These local defects severely limit DEA performance, lifetime, and size scalability. We developed DEAs that can endure more than 100 punctures while maintaining high bandwidth (>400 hertz) and power density (>700 watt per kilogram)—sufficient for supporting energetically expensive locomotion such as flight. We fabricated electroluminescent DEAs for visualizing electrode connectivity under actuator damage. When the DEA suffered severe dielectric breakdowns that caused device failure, we demonstrated a laser-assisted repair method for isolating the critical defects and recovering performance. These results culminate in an aerial robot that can endure critical actuator and wing damage while maintaining similar accuracy in hovering flight. Our work highlights that soft robotic systems can embody animal-like agility and resilience—a critical biomimetic capability for future robots to interact with challenging environments.
Dragonflies are agile and efficient flyers that use two pairs of wings for demonstrating exquisite aerial maneuvers. Compared to two-winged insects such as bees or flies, dragonflies leverage forewing and hindwing interactions for achieving higher efficiency and net lift. Here we develop the first at-scale dragonfly-like robot and investigate the influence of flapping-wing kinematics on net lift force production. Our 317 mg robot is driven by two independent dielectric elastomer actuators that flap four wings at 350 Hz. We extract the robot flapping-wing kinematics using a high-speed camera, and further measure the robot lift forces at different operating frequencies, voltage amplitudes, and phases between the forewings and hindwings. Our robot achieves a maximum lift-to-weight ratio of 1.49, and its net lift force increases by 19% when the forewings and hindwings flap in-phase compared to out-of-phase flapping. These at-scale experiments demonstrate that forewing–hindwing interaction can significantly influence lift force production and aerodynamic efficiency of flapping-wing robots with passive wing pitch designs. Our results could further enable future experiments to achieve feedback-controlled flights.
Insects can navigate in cluttered spaces and perform challenging functions such as pollination and collective object transport. By exploiting scaling laws and bioinspired designs, insect‐scale micro‐aerial‐vehicles (MAVs) have demonstrated impressive flight capabilities such as in‐flight collision resilience and acrobatic maneuvers. However, existing subgram MAVs are difficult to design, construct, and repair. Coupled with challenges in robot sensing and control, existing subgram MAVs have not achieved insect‐like swarm flight, which limits potential studies of swarm behaviors and future applications such as collective sensing. Herein, a new design and fabrication method is developed to substantially improve the fabrication scalability of subgram MAVs. Based on a small set of design parameters, an automated algorithm generates the laser cut files of microrobotic components. To reduce fabrication and assembly time, stereolithographic 3D printing is used for making static components such as the airframe and connectors. The modular design enables straightforward assembly and repair, which reduces the overall fabrication time by over 2 times. Owing to the ease of fabrication and good reliability, two subgram MAVs demonstrate controlled hovering flight and coordinated lifting of an object. This result lays the foundation for future robotic studies of collective insect flight.
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