HAMR - The Harvard Ambulatory MicroRobot

The Harvard Ambulatory Microrobot — nicknamed HAMR — is a versatile robot that can run at high speeds, jump, climb, turn sharply, carry payloads and fall from great distances without being injured. HAMR, with more than 60 joints including hip and legs joints that mimic those of cockroaches, is manufactured using the pop-up microelectromechanical systems (MEMS) fabrication process that enables the construction of small-scale devices with complex 3D topologies and functionalities.

Currently in its sixth generation, this insect scale quadrupedal robot measures 4.5 cm in length and weights a mere 1.43g. Each leg is powered by two piezoelectric actuators allowing it to move along arbitrarily prescribed trajectories. The robot achieves running speeds upto 50 cm/s (over 10 bodylengths per sec) at leg cycling frequency of 45Hz. It can carry a payload of nearly 3.3g (over 2X body weight) with minimal decrease in locomotion performance.

HAMR, with its versatile locomotion capabilities and opportunity for rapid design iteration, also presents a platform that can enable researchers to better understand biological principles in nature by quickly testing hypotheses about locomotion.

Relevant Publications

• Inverted and vertical climbing of a quadrupedal microrobot using electroadhesion. Science Robotics, 3(25), eaau3038, 2018.
• Contact-Implicit Optimization of Locomotion Trajectories for a Quadrupedal Microrobot. Robotics: Science and Systems, Pittsburg, Jun 26-30, 2018.
• Concomitant sensing and actuation for piezoelectric microrobots. Smart Materials and Structures, 27(6), 065028, 2018.
• A high speed motion capture method and performance metrics for studying gaits on an insect-scale legged robot. International Conference on Intelligent Robots and Systems, Vancouver, Candada Sept 24-28, 2017.
• Gait studies for a quadrupedal microrobot reveal contrasting running templates in two frequency regimes. Bioinspiration and Biomimetics, 12(4):046005, 2017.
• Phase control for microrobots running near resonance. International Conference on Robotics and Automation, Singapore, May 29- Jun 3, 2017.