A robot leg based on mammalian muscle architecture

Most legged robots to date use individual motors at the joints for actuation. However, the muscle structure of vertebrate legs incorporates both a flexor-extensor architecture and biarticular muscles — muscles that span two joints. Flexor-extensor architecture enables the joint to swing freely when muscles are relaxed, while biarticular muscles have been shown to play an important role in transferring power from proximal to distal body parts, enabling high-powered motions such as running and jumping. In this paper, we present a robot leg based on the muscle structure of the human leg, incorporating biarticular muscles and a flexor-extensor architecture. We demonstrate that this robot leg is able to use it's biarticular “muscles” to transfer power from the upper limb to the ankle, mimicking key characterisitics of the human leg.