  Here we present HAMR-Jr, a \SI{22.5}{\milli\meter}, \SI{320}{\milli\gram}
quadrupedal microrobot. With eight independently actuated degrees of freedom,
HAMR-Jr is, to our knowledge, the most mechanically dexterous legged robot at
its scale and is capable of high-speed locomotion
(\SI{13.91}{bodylengths~\second^{-1}}) at a variety of stride frequencies
(\SI{1}{}-\SI{200}{\hertz}) using multiple gaits. We achieved this using a
design and fabrication process that is flexible, allowing scaling with minimum
changes to our workflow. We further characterized HAMR-Jr's open-loop
locomotion and compared it with the larger scale HAMR-VI microrobot to
demonstrate the effectiveness of scaling laws in predicting running
performance.
