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

Physical scaling laws predict that miniaturizing robotic mechanisms should enable exceptional robot performance in metrics such as speed and precision. Although these scaling laws have been explored in a variety of microsystems, the benefits and limitations of downscaling three-dimensional (3D) robotic mechanisms have yet to be assessed because of limitations in microscale 3D manufacturing. In this work, we used 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 and 0.7 millimeters in height, which demonstrate state-of-the-art performance in both size and speed compared with previously reported Delta robots. Printing with two-photon polymerization and subsequent metallization enabled the miniaturization of these 3D robotic parallel mechanisms integrated with electrostatic actuators for achieving high bandwidths. The smallest microDelta was able to operate at more than 1000 hertz and achieved precisions of less than 1 micrometer 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.