Harvard’s RoboBee, a marvel of microrobotics, now lands with the finesse of a crane fly, thanks to innovative leg designs and advanced control systems that promise safer touchdowns and broader applications.
Key Points at a Glance
- RoboBee is equipped with crane fly-inspired legs for improved landing stability.
- Enhanced control systems allow for deceleration and energy dissipation upon landing.
- Design improvements protect delicate piezoelectric actuators from damage.
- The robot’s size and weight make landing particularly challenging due to ground effects.
- Future developments aim for full autonomy with onboard sensors and power systems.
The RoboBee, developed by Harvard’s Microrobotics Laboratory, has long showcased its ability to fly, hover, and dive like a real insect. However, achieving a controlled and gentle landing remained a significant hurdle. Weighing just a tenth of a gram with a wingspan of 3 centimeters, the RoboBee’s lightweight design made it susceptible to instability caused by air vortices near the ground, known as ground effect.
To address this, the research team, led by Professor Robert Wood, drew inspiration from the crane fly, an insect known for its graceful landings. They equipped the RoboBee with long, jointed legs that mimic the crane fly’s appendages, allowing the robot to absorb impact forces effectively. These legs were designed using data from Harvard’s Museum of Comparative Zoology and manufactured with techniques developed in the Microrobotics Lab to fine-tune joint stiffness and damping.
In addition to mechanical enhancements, the RoboBee’s control system was upgraded to manage deceleration during descent. This advancement enables the robot to minimize velocity before impact and dissipate energy quickly upon landing, reducing the risk of bouncing or tumbling. Co-first author Nak-seung Patrick Hyun, now at Purdue University, led the development of these control algorithms and conducted landing tests on various surfaces, including leaves and rigid platforms.
These improvements are crucial for protecting the RoboBee’s piezoelectric actuators, which serve as its flight muscles. These actuators are energy-dense but fragile, making them vulnerable to damage from rough landings. By ensuring smoother touchdowns, the new design extends the robot’s operational lifespan and reliability.
The RoboBee remains tethered to external power and control systems, but the research team aims to achieve full autonomy by integrating onboard sensors, power sources, and control units. Such advancements would enable the RoboBee to operate independently, opening doors to applications in environmental monitoring, disaster response, and artificial pollination.
This study exemplifies the synergy between biology and engineering, demonstrating how understanding natural organisms can lead to significant technological breakthroughs. As the RoboBee project continues to evolve, it holds promise for transforming various fields through its innovative design and capabilities.
Source: Harvard John A. Paulson School of Engineering and Applied Sciences
