Combustion-Powered Insect-Scale Robot from Cornell Researchers Outperforms Electric Competitors
In a groundbreaking study published in Science, Cornell researchers have developed a combustion-powered quadrupedal robot that surpasses its electric-driven counterparts in speed, strength, flexibility, and leaping ability. The team, led by Rob Shepherd, associate professor of mechanical and aerospace engineering, combined soft microactuators with high-energy-density chemical fuel to create this tiny powerhouse.
Revolutionizing Robots at Insect Scale
Despite their small size, insects possess remarkable strength and capabilities. However, replicating these abilities in insect-scale robots poses significant challenges. Traditional motors and pumps do not function effectively when scaled down to this size. As a result, researchers have resorted to creating custom mechanisms. Previously, these robots relied on tethered power sources, usually electricity.
Recognizing the limitations of electric-powered robots, the Cornell team sought to enhance the onboard power and performance of insect-scale robots. They achieved this by utilizing a high-energy-density chemical fuel, akin to automobile fuel. This innovative approach enables the robot to operate for an hour with just a milliliter of fuel, outweighing the constraints of heavy batteries.
Unmatched Performance and Potential
Although the robot is not yet fully untethered, it already surpasses its competitors in terms of force output. Weighing only one and a half paperclips and measuring just over an inch long, this 3D-printed, four-legged robot is a true powerhouse. It contains a pair of combustion chambers linked to four actuators, which serve as its feet. When sparking is initiated by offboard electronics, the combustion reaction inflates the actuators, propelling the robot upwards.
These unique actuators generate an impressive force of 9.5 newtons, dwarfing the approximately 0.2 newtons produced by similarly sized robots. Furthermore, the robot operates at frequencies exceeding 100 hertz and achieves displacements of 140%, demonstrating its exceptional capabilities. It can even lift 22 times its body weight.
With combustion as its power source, the robot can excel in various challenging terrains, navigate obstacles, and exhibit incredible jumping ability and speed. These accomplishments stem from the exceptional force and power density of its fuel-driven actuators.
Precise Control and Future Prospects
The robot’s actuator design enables precise control. By manipulating sparking speed, frequency, and fuel supply, the operator can produce a range of responses. From skittering across the ground to slowing down and hopping, and even leaping 60 centimeters in the air, this robot defies expectations for its size.
The researchers plan to expand the capabilities of this technology by connecting more actuators in parallel arrays. This advancement will allow the robot to produce both fine and forceful movements on a larger scale. Additionally, the team aims to develop an untethered version powered by liquid fuel, reducing the need for bulky external components.
This breakthrough in robot performance opens up a world of possibilities. Insect-scale robots empowered by these fuels can revolutionize search and rescue operations, exploration, environmental monitoring, surveillance, and navigation in challenging environments.
The study received support from the Air Force Office of Scientific Research, the National Science Foundation, and the Office of Naval Research.