Here is a 6cm long swimmer/crawler robot that uses a wave motion to move around. It uses a single motor for actuation. Since the motor and battery were heavy, floats were needed for this robot. This SAW robot was made by Rotem Katz, Omer Guetta, Dan Shachaf, and David Zarrouk at the Bioinspired and Medical Robotics Lab at the Ben Gurion University of the Negev.
[HT]