Design of a 5-cm monopod hopping robot

The monopod hopper described fits into a cube that is 5 cm on a side, is autonomous, and is designed to be statically stable and passively dynamically stable. Hopping is achieved through the excitation of a spring-mass system at its resonant frequency. Simulations were extensively used to finalize the design, before construction of the robot. The hopper, although having no active directional control, is able to climb steps up to 1 mm, travel at a rate of 1.5 body lengths per second for an average of over 225 cm before deviating significantly from its original course, and can operate up to 45 min before depleting the energy stored in the batteries.