Rapid Manufacture of Novel Variable Impedance Robots using Waterjet Cutting and 3D Printing

Variable stiffness and variable damping can play an important role in robot movement, particularly in legged robots such as bipedal walkers. Variable impedance also introduces new control problems, since there are more degrees of freedom to control, and the resulting robot has more complex dynamics. Among other applications, we are investigating the effects of impedance variation and physical compliance on bipedal locomotion. In order to do this it we have developed novel bipedal robots which can vary both the stiffness and damping of their joints, independently of the joint's output position. As a lab which primarily develops algorithms, we only have access to very limited manufacturing facilities, and must factor this in when developing hardware to be built. Rapid manufacturing technology allows for cost effective outsourcing of parts, but each process has its limitations. We present our experiences in producing bipedal robots with variable impedance joints using waterjet cutting, 3D printing, and posit that combining these two techniques provides a simple, fast, and cost effective way to produce robotic hardware.