© Georgia Institute of Technology, Allison Carter

... from a piezoelectric shaker under the surface on which the robot moves, from an ultrasonic / sonar source or even from a tiny acoustic speaker. The vibrations move the springy legs up and down and propel the micro-bot forward. Depending on the leg size, diameter, design and overall geometry, each robot can be designed to respond to different vibration frequencies. The amplitude of the vibrations controls the speed at which the micro-bot moves: in one second, the robot can ...