Fundamental understanding of millipede morphology and locomotion dynamics.

A detailed model for the locomotory mechanics used by millipedes is provided here through systematic experimentation on the animal and validation of observations through a biomimetic robotic platform. Millipedes possess a powerful gait that is necessary for generating large thrust force required for proficient burrowing. Millipedes implement a metachronal gait through movement of many legs that generates a traveling wave. This traveling wave is modulated by the animal to control the magnitude of thrust force in the direction of motion for burrowing, climbing, or walking. The quasi-static model presented for the millipede locomotion mechanism matches experimental observations on live millipedes and results obtained from a biomimetic robotic platform. The model addresses questions related to the unique morphology of millipedes with respect to their locomotory performance. A complete understanding of the physiology of millipedes and mechanisms that provide modulation of the traveling wave locomotion using a metachronal gait to increase their forward thrust is provided. Further, morphological features needed to optimize various locomotory and burrowing functions are discussed. Combined, these results open opportunity for development of biologically inspired locomotory methods for miniaturized robotic platforms traversing terrains and substrates that present large resistances.