This past summer I spent the majority of my time designing and developing  a low-cost prototype robotic arm to thread suture through small holes in a biodegradable patch used in a vascular medical device. The PRR-type arm was designed with Pro/Engineer, and completely manufactured in-house using a Zortrax M200 3D printer. The arm used a combination of stepper motors and high definition incremental rotary encoders to achieve the high positioning accuracy (as low as 0.02 degrees per joint) necessary to align the precision parts.