Engineers from Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS) developed the original HAMR (Harvard Ambulatory Microrobot) in 2018 using a design inspired by cockroaches. The robot could run at high speeds, jump, climb, turn sharply, carry payloads, and fall from great distances without being harmed. That said, the robot was a bit chunky, measuring out at 5cm and weighing around 3g.
The team has since reduced its dimensions and weight with the HAMR-Jr, a smaller version of the original about the size of a penny, but can still take a beating and keep on functioning. The robot was made using the PC-MEMS (Printed Circuit Microelectromechanical Systems) manufacturing method, which involves using a micro-layered building material, then a laser to cut it into patterns. The different panels are hinged together, which can he be folded into 3D shapes, much like origami.
With HAMR-Jr, the engineers just scaled the 2D design pattern down to just 2.25cm, along with the leg actuators and onboard circuitry. Power is provided via a tethered external source, and the robot doesn’t feature any autonomous software, as of yet. The robot is outfitted with tiny piezoelectric actuators that drive it forward at a rate of nearly 14 body lengths per second using a gate frequency of 200MHz.
The frequency can be pushed to 300MHz, but the robot loses speed at this point as the 200MHz range hits a resonant “sweet spot” that gives it the best leg lift and stride length for mobile efficiency. Since the HAMR-Jr can be scaled, it will be interesting to see how it will evolve over the next two years and what it will be capable of at that point.