Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have equipped the RoboBee microrobot with a new landing system modeled after the legs of crane flies, aiming to improve its ability to land safely. The development, detailed in the journal Science Robotics, marks a new phase in the RoboBee project, which has previously demonstrated the robot’s capacity for insect-like flight behaviors such as hovering and diving.
The latest modification introduces long, jointed legs to the microrobot, designed to mimic the mechanical structure of crane fly appendages. These legs help reduce impact forces during landing, a critical consideration due to the fragility of the robot’s piezoelectric actuators that power its flight. At just one-tenth of a gram in weight and with a wingspan of 3 centimeters, RoboBee is particularly vulnerable to damage from landing-related instability and ground effects—air disturbances caused by the flapping of its wings near the ground.
To address these issues, the research team improved the robot’s controller system to better manage deceleration and compensate for ground effects during descent. This redesign was led by graduate student Christian Chan and former postdoctoral researcher Nak-seung Patrick Hyun, who also conducted tests of the robot’s landing performance on both rigid and flexible surfaces.
The project incorporated biological research into insect locomotion, drawing on the morphology and joint structure of crane flies, which are known for their delicate landings and short, frequent flights. The team used manufacturing techniques developed at the Harvard Microrobotics Lab to fine-tune the stiffness and damping properties of the robot’s new legs.
Biologist Alyssa Hernandez contributed to the integration of biological principles into the robot’s design. She emphasized the value of using RoboBee as a tool for investigating biomechanical functions in insects, suggesting the platform could serve dual roles in both engineering and biological research.
While the RoboBee remains tethered to off-board control systems, the team is working toward full autonomy by developing onboard sensors, power sources, and control mechanisms. Lead researcher Robert Wood highlighted safe landing capabilities as a necessary step toward untethering the robot and advancing toward autonomous operation.
Potential future applications of the RoboBee platform include environmental monitoring, disaster response, and artificial pollination, although these remain areas for further exploration as the robot’s capabilities continue to evolve.
Photo credit: Eliza Grinnell / Harvard SEAS Communications
