Researchers from Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS) have upgraded their RoboBee with soft artificial muscles that are capable of withstanding impacts without being damaged. Previous versions were outfitted with rigid technology and often broke when careening into walls or falling to the floor.
According to SEAS, it’s the first microrobot to take flight powered by soft actuators. The push for soft actuators outfitted on small robots have risen over the years, but scientists were skeptical that they could be incorporated into flying robots as the power density of those actuators is challenging to control.
To get around that issue, the SEAS team developed electrically-driven soft actuators using dielectric elastomers, which feature insulating properties that deform when an electric field is introduced. Improving the actuator’s electrode conductivity allowed the researchers to operate them at the 500Hz range, the same range its rigid counterpart featured in previous RoboBees.
Another problem the scientists faced are soft actuators tend to buckle, becoming unstable. To counteract this issue, they built a lightweight airframe with a vertical constraining thread, which prevents the actuator from buckling. What’s more, the soft actuators can be easily assembled and replaced in those small-scale robots.
To test their new technology, the scientists designed several differently configured RoboBees to demonstrate their flight capabilities- a two-wing model that could take off from the ground but had no control, and a four-wing dual-actuator version capable of flying in a cluttered environment. Additionally, an eight-wing quad-actuator model was capable of sustaining hovered flight. The scientists state their next objective is to increase the efficiency of the RoboBees, which apparently lag far behind traditional flying robots.