The microDelta: Downscaling robot mechanisms enables ultra-fast and high precision movement

Physical scaling laws predict that miniaturization of robotic mechanisms
should enable exceptional robot performance on metrics such as speed and
precision. While these scaling laws have been explored in a variety of
microsystems, the benefits and limitations of downscaling 3D robotic
mechanisms have yet to be assessed due to limitations in microscale 3D
manufacturing. In this work, we use the Delta robot as a case study for
these scaling laws. We present two sizes of 3D-printed Delta robots, the
microDeltas, measuring 1.4 mm and 0.7 mm in height, which are the smallest
and fastest Delta robots ever demonstrated. 3D printing with two-photon
polymerization and subsequent metallization enabled the miniaturization of
these 3D robotic parallel mechanisms integrated with electrostatic
actuators for exceptionally high bandwidths. The smallest microDelta was
able to operate at over 1000 Hz and achieved precisions of less than 1 µm
by taking advantage of its small size. The microDelta's relatively
high output power was demonstrated with the launch of a small projectile,
highlighting the utility of miniaturized robotic systems for applications
ranging from manufacturing to haptics.