US Patent 7351290 Robotic pen

A robotic pen includes a computer numerically controlled machine having a multiaxis stage for mounting a workpiece, and a cooperating elevator which translates relative thereto. A pen tip is rotatably mounted to the elevator. And, a dispenser is joined in flow communication with the pen tip for ejecting a stream of material atop the workpiece as the workpiece moves relative thereto for maintaining a substantially constant gap between said pen tip and the workpiece during relative movement therebetween.