A Piezoelectric Water Skating Microrobot Steers Through Ripple Interference

This work reports a 4-cm-long piezoelectric microrobot with agile steering abilities on water surface. Two unique accomplishments are demonstrated: (1) A 0.88g soft robot uses two pairs of flapping hydrofoils (equal frequency but with phase offsets) to generate adjustable thrusts that cause smoothly steering on water surface (first in published papers). The robot's angular velocity ranges from -6°/s (clockwise) to +6°/s (counterclockwise), and the turning resolution is 0.4°/s; (2) The soft robot that made of fully flexible structures has a forward skating speed up to 2cm/s, and carries loads of three times its weight with the speed of 4mm/s. As such, the new method could open up new opportunities for microrobots working on water surface.